#include<iostream>
using namespace std;
int main (void) {
    int a,b;
    cin >> a >> b;
    int k=1;
    for (int i=1;i<=b;++i) {
        k=k*10;
    }
    int r=a % k;
    if (r>k/2-1) {
        cout << a+(k-r);
    }
    else {
        cout << a-r;
    }
    return 0;
}