from sys import stdin
rs = lambda : stdin.readline().strip()
ri = lambda : int(rs())
ril = lambda : list(map(int, rs().split()))

def main():
    S = rs()
    for i in range(26):
        if S[i] != chr(ord('a') + i):
            ans = chr(ord('a') + i) + 'to' + S[i]
            break
    print(ans)

if __name__ == '__main__':
    main()