17

#include <iostream>

int readNumber(std::istream& in) {
    int ret = 0;
    while (true) {
        int a = in.get();

        if (a <= 0 || a == '\n') break;
        if (!(a >= '0' && a <= '9')) break;

        int num = a - '0';
        ret *= 10;
        ret += num;
    }
    return ret;
}

int main() {
    std::cout << readNumber(std::cin) << "\n";
}