#include<bits/stdc++.h>
using namespace std;

int main() {
    int n,x,y;
    cin>>n>>x>>y;;
    int ans=100;
    for(int i=0;i<=n/x;i++) {
        int dis=n-i*x;
        if(dis%y==0)ans=min(ans,n-i*x-(dis%y-1)*y);
        else ans=min(ans,n-i*x-dis/y*y);
    }
    cout<<ans;
}