#include<iostream>
#include<string>
#include<cmath>

using namespace std;

int main() {
    string input;
    if(!(cin >> input)) {
        cout<< "Invalid input";
            return 0;
        }
        
        int startldx =0;
        bool hasDigits = 0;
        
        if(input[0] == '-') {
            startldx = 1;
            if(input.length() == 1) {
                cout << "Invalid input" << endl;
                return 0;
            }
        }
        for(int i= startldx; i < input.length(); i++) {
            if(!isdigit(input[i])) {
                cout << "Invalid input" << endl;
                return 0;
            }
            
            cout << digiCount << endl;
            
            return 0;
        }
    }