#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstdlib>

using namespace std;
long long n,l,k1,r,k2=0;
int main()
{
    freopen("candy.in","r",stdin);
    freopen("candy.out","w",stdout);
    scanf("%d%d%d",&n,&l,&r);
    for(long long i=l;i<=r;i++)
    {
        k1=i%n;
        if(k1>=k2)k2=k1;
    }
    cout<<k2;
    return 0;
}