# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	S = input()
	for i in range(26):
		if ord(S[i]) - (97 + i) != 0:
			ans = chr(97 + i) + "to" + S[i]
			print(ans)
			return
			

if __name__ == '__main__':
	main()