function ctos(c) {
  return String.fromCharCode(c)
}
function test(n) {
  var result = []
  do {
    result.push((n % 26) + 65);
    n = (n / 26) - 1;
  } while (n >= 0);
  return result
    .reverse()
    .map(ctos)
    .join("")
}
function Main(input) {
  var input = input.split('\n')[0];
  var N = parseInt(input)
  console.log(N, test(N))
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));