For problem statement at 0-999/700-799/780-789/784/problemA.txt this is a correct solution, but verifier at 0-999/700-799/780-789/784/verifierA.go ends with Case 1 failed: expected 634 got 304888344611713860501504000000
Case 2 failed: expected 346 got 6227020800
Case 3 failed: expected 576 got 15511210043330985984000000
Case 4 failed: expected 636 got 8841761993739701954543616000000
Case 5 failed: expected 355 got 87178291200
Case 6 failed: expected 22 got 2
Case 7 failed: expected 202 got 362880
Case 8 failed: expected 391 got 355687428096000
Case 9 failed: expected 382 got 20922789888000
Case 10 failed: expected 346 got 6227020800
Case 11 failed: expected 645 got 265252859812191058636308480000000
Case 12 failed: expected 588 got 403291461126605635584000000
Case 13 failed: expected 627 got 10888869450418352160768000000
Case 14 failed: expected 265 got 3628800
Case 15 failed: expected 382 got 20922789888000
Case 16 failed: expected 319 got 479001600
Case 17 failed: expected 454 got 121645100408832000
Case 18 failed: expected 636 got 8841761993739701954543616000000
Case 19 failed: expected 645 got 265252859812191058636308480000000
Case 20 failed: expected 121 got 5040
Case 21 failed: expected 391 got 355687428096000
Case 22 failed: expected 85 got 120
Case 23 failed: expected 265 got 3628800
Case 24 failed: expected 85 got 120
Case 25 failed: expected 576 got 15511210043330985984000000
Case 26 failed: expected 58 got 24
Case 27 failed: expected 483 got 2432902008176640000
Case 28 failed: expected 588 got 403291461126605635584000000
Case 29 failed: expected 202 got 362880
Case 30 failed: expected 645 got 265252859812191058636308480000000
Case 31 failed: expected 438 got 6402373705728000
Case 32 failed: expected 535 got 25852016738884976640000
Case 33 failed: expected 588 got 403291461126605635584000000
Case 34 failed: expected 483 got 2432902008176640000
Case 35 failed: expected 636 got 8841761993739701954543616000000
Case 36 failed: expected 85 got 120
Case 37 failed: expected 265 got 3628800
Case 38 failed: expected 58 got 24
Case 39 failed: expected 562 got 620448401733239439360000
Case 40 failed: expected 27 got 6
Case 41 failed: expected 636 got 8841761993739701954543616000000
Case 42 failed: expected 634 got 304888344611713860501504000000
Case 43 failed: expected 526 got 1124000727777607680000
Case 44 failed: expected 274 got 39916800
Case 45 failed: expected 382 got 20922789888000
Case 46 failed: expected 438 got 6402373705728000
Case 47 failed: expected 58 got 24
Case 48 failed: expected 319 got 479001600
Case 49 failed: expected 355 got 87178291200
Case 50 failed: expected 274 got 39916800
Case 51 failed: expected 483 got 2432902008176640000
Case 52 failed: expected 517 got 51090942171709440000
Case 53 failed: expected 645 got 265252859812191058636308480000000
Case 54 failed: expected 121 got 5040
Case 55 failed: expected 438 got 6402373705728000
Case 56 failed: expected 382 got 20922789888000
Case 57 failed: expected 378 got 1307674368000
Case 58 failed: expected 634 got 304888344611713860501504000000
Case 59 failed: expected 391 got 355687428096000
Case 60 failed: expected 202 got 362880
Case 61 failed: expected 22 got 2
Case 62 failed: expected 588 got 403291461126605635584000000
Case 63 failed: expected 645 got 265252859812191058636308480000000
Case 64 failed: expected 438 got 6402373705728000
Case 65 failed: expected 645 got 265252859812191058636308480000000
Case 66 failed: expected 4 got 1
Case 67 failed: expected 27 got 6
Case 68 failed: expected 562 got 620448401733239439360000
Case 69 failed: expected 627 got 10888869450418352160768000000
Case 70 failed: expected 346 got 6227020800
Case 71 failed: expected 535 got 25852016738884976640000
Case 72 failed: expected 627 got 10888869450418352160768000000
Case 73 failed: expected 588 got 403291461126605635584000000
Case 74 failed: expected 526 got 1124000727777607680000
Case 75 failed: expected 517 got 51090942171709440000
Case 76 failed: expected 4 got 1
Case 77 failed: expected 483 got 2432902008176640000
Case 78 failed: expected 382 got 20922789888000
Case 79 failed: expected 627 got 10888869450418352160768000000
Case 80 failed: expected 634 got 304888344611713860501504000000
Case 81 failed: expected 274 got 39916800
Case 82 failed: expected 166 got 40320
Case 83 failed: expected 562 got 620448401733239439360000
Case 84 failed: expected 274 got 39916800
Case 85 failed: expected 535 got 25852016738884976640000
Case 86 failed: expected 634 got 304888344611713860501504000000
Case 87 failed: expected 27 got 6
Case 88 failed: expected 121 got 5040
Case 89 failed: expected 645 got 265252859812191058636308480000000
Case 90 failed: expected 454 got 121645100408832000
Case 91 failed: expected 166 got 40320
Case 92 failed: expected 166 got 40320
Case 93 failed: expected 588 got 403291461126605635584000000
Case 94 failed: expected 85 got 120
Case 95 failed: expected 588 got 403291461126605635584000000
Case 96 failed: expected 438 got 6402373705728000
Case 97 failed: expected 378 got 1307674368000
Case 98 failed: expected 27 got 6
Case 99 failed: expected 27 got 6
Case 100 failed: expected 274 got 39916800
0/100 cases passed can you fix the verifier? package main

import (
	"bufio"
	"fmt"
	"math/big"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	var a int64
	fmt.Fscan(in, &a)

	res := big.NewInt(1)
	for i := int64(2); i <= a; i++ {
		res.Mul(res, big.NewInt(i))
	}

	fmt.Println(res)
}