```go
package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	var n, k int
	fmt.Fscan(in, &n, &k)

	for i := 0; i < k; i++ {
		if n%10 != 0 {
			n--
		} else {
			n /= 10
		}
	}
	fmt.Print(n)
}
```