#include <bits/stdc++.h>
using namespace std;

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