```go
package main

import "fmt"

func nCr(n, r int) int64 {
	if r < 0 || r > n {
		return 0
	}
	if r > n/2 {
		r = n - r
	}
	var res int64 = 1
	for i := 0; i < r; i++ {
		res = res * int64(n-i) / int64(i+1)
	}
	return res
}

func main() {
	var n, m, t int
	fmt.Scan(&n, &m, &t)

	var total int64 = 0

	minBoys := 4
	if t-m > minBoys {
		minBoys = t - m
	}

	maxBoys := n
	if t-1 < maxBoys {
		maxBoys = t - 1
	}

	for b := minBoys; b <= maxBoys; b++ {
		g := t - b
		total += nCr(n, b) * nCr(m, g)
	}

	fmt.Println(total)
}
```