#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
#include <unordered_map>
#include <functional>
#include <unordered_set>
#include <string>
#include <set>
#include <utility>
#include <queue>

int main() {
    int N, sum = 0;
    std::string number;
    std::cin >> N;
    std::cin >> number;
    if (N == 1) {
        std::cout << 0;
    } else {
        std::vector<int> r;
        r.resize(number.size() - 1);
        int r1 = 1;
        for (int i = 0; i < r.size(); i++) {
            r[i] = r1 * 10 % N;
            r1 = r[i];
        }
        int j = 1;
        long long summ = 0;
        summ += (number[number.size() - j]) - '0';
        j++;
        for (int i = 0; i < r.size(); i++) {
            summ += ((number[number.size() - j]) - '0') * r[i];
            j++;
        }
        std::cout << summ % N;
    }
}