#include<iostream>
using namespace std;

class Person {
    public:
    string name;
    int age;
    
    void operator++() {
        ++age;
    }
};
int main() {
    person ;
    cin >> p.name >> p.age;
    
    if(p.age < 0) {
        cout << "Invalid input";
        return 0;
    }
    ++p;
    cout << p.name << ": " << p.age;
    return 0;
}