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

为啥我在DEV-C++里能输出而且对了