Çàäà÷à . (C++) Óñëîâíûé îïåðàòîð (if ... else)

#include <iostream>             

using namespace std;             

int main()             

{             

    int n;             

    cin >> n;             

    if (__)             

    {             

        __   

    }             

    else             

    {             

        cout << "+" << endl;           

    }             

    return 0;             

}