Day of the Programmer

#include <bits/stdc++.h>

using namespace std;

string ltrim(const string &);
string rtrim(const string &);

// Complete the dayOfProgrammer function below.
string dayOfProgrammer(int year) {
string day = "";

if (year % 4 == 0)
    {
        if (year % 100 == 0)
        {
            if (year % 400 == 0)
               day = "12.09." + to_string(year);
               // cout << year << " is a leap year.";
            else
              day = "13.09."+ to_string(year);
              //  cout << year << " is not a leap year.";
        }
        else
        day = "12.09."+ to_string(year);
          //  cout << year << " is a leap year.";
    }
    else
    day = "13.09."+ to_string(year);
      //  cout << year << " is not a leap year.";

return day;
}

int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));

    string year_temp;
    getline(cin, year_temp);

    int year = stoi(ltrim(rtrim(year_temp)));

    string result = dayOfProgrammer(year);

    fout << result << "\n";

    fout.close();

    return 0;
}

string ltrim(const string &str) {
    string s(str);

    s.erase(
        s.begin(),
        find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
    );

    return s;
}

string rtrim(const string &str) {
    string s(str);

    s.erase(
        find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
        s.end()
    );

    return s;
}


Failed against: 1700, 1800