#include<bits/stdc++.h> 
using namespace std; 
int L,R,n; 
int main() 
{ 
	scanf("%d%d%d",&n,&L,&R); 
	int x1,x2,x3; 
	x1=L/n; 
	x2=(x1+1)*n; 
	if(x2<=R) 
	cout<<n-1; 
	if(x2>R) 
{ 
	x3=max(L%n,R%n); 
	cout<<x3; 
} 
	return 0; 
}