977A - Wrong Subtraction.cpp

#include "iostream";

using namespace std;

int main()
{
    int n, k;

    cin >> n >> k;

    for (int i = 0; i < k; ++i)
    {
        if (n % 10 == 0)
            n /= 10;
        else
            n -= 1;
    }

    cout << n;

    return 0;
}