Codeforces 977A A. Wrong Subtraction Solution

Solve in C++:

//AH Tonmoy
//Department of CSE ,Islamic University

#include<bits/stdc++.h>
using namespace  std;
int main()
{
int n,k,i;
while(cin>>n>>k)
{
    for(i=1;i<=k;i++)
    {
        if(n%10>0)
        n--;
        else
        n=n/10;
    }
    cout<<n<<endl;
    n=0;
}
}