include <bits/stdc++.h>

using namespace std;

int main() {

int n, k;
cin >> n >> k;
for (int i = 0; i < k; i++) {
	if (n % 10 != 0) {
		n -= 1;
	}
	else if(n % 10 == 0) {
		n /= 10;
	}
}
cout << n;
return 0;

}