`
string timeConversion(string s) {
    int n = s.size();
    string hourStr = s.substr(0,2);
    int hour = std::stoi( hourStr);
    if (s[n-2]=='P' && hour<12) {
        hour+=12 ;
        hourStr = to_string(hour);
    }
    if (s[n-2]=='A' && hour==12) {
        hourStr = "00";
    }
    s = hourStr.append(s.substr(2,n-4));
    
    return s;

}