#!/usr/bin/env python3
# from typing import *


# def solve(S: str) -> str:
def solve(S):
    for x, y in zip('abcdefghijklmnopqrstuvwxyz', S):
        if x != y:
            return x + 'to' + y


# generated by online-judge-template-generator v4.6.0 (https://github.com/online-judge-tools/template-generator)
def main():
    S = input()
    a = solve(S)
    print(a)


if __name__ == '__main__':
    main()