using System;

public class Program{

    public void Main(){

        Console.WriteLine(GetExcelColumnName(702));

    }

    private string GetExcelColumnName(int columnNumber){

        string columnName = "";

    while (columnNumber > 0)

    {

        int modulo = (columnNumber - 1) % 26;

        columnName = Convert.ToChar('A' + modulo) + columnName;

        columnNumber = (columnNumber - modulo) / 26;

    }  

    return columnName;

    }

}