#!/usr/bin/python
# -*- coding: utf-8 -*-
"""Minimal FORTRAN-style Markov text generator."""
import sys
import random
import bisect

if __name__ == '__main__':
    model = [[0 for ii in range(256)] for jj in range(256)]
    last = -1
    for c in sys.stdin.read():
        c = ord(c)
        if last != -1:
            model[last][c] += 1
        last = c

    for ii in range(256):
        for jj in range(1, 256):
            model[ii][jj] += model[ii][jj-1]

    for ii in range(1024):
        sys.stdout.write(chr(c))
        while model[c][-1] == 0:
            c = random.randrange(256)
        c = bisect.bisect_right(model[c], random.randrange(model[c][-1]))