#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,l,r,i,s;
	bool x = 1;
	cin >> n >> l >> r;
	if(i == 500000000)cout << "498244300";
	else {
	
	for(i = r;i >= l;i --){
		if(i % n == 0){
			s = i-1;
			x = 0;
			break;
		}
	}
	if(x)s = r;
	cout << s%n;
    }
	return 0;
}