Is the year leap or not

#include <iostream>
using namespace std;

string leap(int y)
{
    if (y % 100 == 0 && y % 400 == 0)
    {
        return "leap";
    }
    else if (y % 100 == 0 && y % 400 != 0)
    {
        return "not leap";
    }
    else if (y % 4 == 0)
    {
        return "leap";
    }
    else if (y % 4 != 0)
    {
        return "not leap";
    }
    else return "error";
}

int main()
{
    int y;
    cout << " Insert a year: \n";
    cin >> y;
    cout << " Year is: \n " << leap(y) <<"\n";
    cout << " Insert a year: \n";
    cin >> y;
    cout << " Year is: \n " << leap(y) << "\n";
    cout << " Insert a year: \n";
    cin >> y;
    cout << " Year is: \n " << leap(y) << "\n";
}