#include<bits/stdc++.h>
using namespace std;
bool cmp(int x,int y){
	return x>y;
}
int main(){
	int n,l,r,max=0;
	scnaf("%d",&n);
	scnaf("%d",&l); 
	scnaf("%d",&r);  
	for(;l<=r;l++){
		int q=l;
		while(q>=n){
			q%=n;
		}
		if(q>max) max=q;
	}
	printf("%d",max);
	return 0;
}
/**************************************************************
	Problem: 2401
	User: houshanglin
	Language: C
	Result: Compile Error
****************************************************************/