#include<bits/stdc++.h>
using namespace std;
long long n,l,r,k,Max=-1;
int main(){
//freopen("candy.in","r",stdin);
//freopen("candy.out","w",stdout);
cin>>n>>l>>r;
for(int i=l;i<=r;i++){
k=i%n;
Max=max(k,Max);
}
cout<<Max;
return 0;
}
O(R−L) 大概是 109 开 -O2
能过吗……