#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<vector>
#include<map>
using namespace std;
int n,ma,mi;
int main(){
	scanf("%d %d %d",&n,&mi,&ma);
	printf("%d",((ma-mi)/n!=0)*(n-1)
        +((ma-i)/n==0)*(ma%n));
        return 0;
}