#include <iostream>
#include <cmath>
struct NumberHolder{
    int number;
};
int SumDigits(const NumberHolder& nh){
    if (nh.number <0){
    return -1;
}
int num = nh.number;
int sum =0;
if (num == 0){
    return 0;
}
while (num >0){
    sum += num % 10;
    num /=10;
}
return sum;
}
int main(){
    int n_input;
    std::cin >> n_input;
    if (n_input < -1000 || n_input > 1000){
        std::cout << "Invalid input" << std::end1;
    }else {
        std::cout << result << std::end1;
    }
    return 0;
}