#382 AproapeK

#include <iostream>

using namespace std;

int main()
{
    int n,k,a,b;
    cin>>k>>n;
    a=k/n;
    b=a+1;
    if(k-n*a<=n*b-k)
    cout<<n*a;
    else
    cout<<n*b;
    return 0;
}