python/TangDou/CSP-J/J2-2021/1_1.cpp

#include <iostream>
using namespace std;
int main() {
    int n, L, R;
    cin >> n >> L >> R;
    if (R / n > L / n)
        cout << n - 1 << endl;
    else
        cout << R % n << endl;
    return 0;
}