#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,l,r,s1,s2;
	scanf("%d",&n);
	scanf("%d",&l); 
	scanf("%d",&r);
	s1=l/n+1;//16/7=2 2, 
	s2=s1*n;
	if(s2<=r) printf("%d",n-1);
	else printf("%d",n-(s2-r));
	return 0;
}
/**************************************************************
	Problem: 2401
	User: houshanglin
	Language: C++
	Result: Accepted
	Time:37 ms
	Memory:2076 kb
****************************************************************/