C++ :

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

int main()
{
	int n,l,r;
	scanf("%d%d%d",&n,&l,&r);
	if(r-l>=n) printf("%d",n-1);
	else
	{
		int t=l%n;
		int f=r%n;
		if(f<t) printf("%d",n-1);
		else printf("%d",f);
	}
	return 0;
}