#!/usr/bin/env python3
from itertools import combinations, permutations

def k_permutations(set_, k):
    for comb in combinations(set_, k):  # (10*9*8*7) / (4*3*2)
        yield from permutations(comb)   # 4!

for code in k_permutations(range(10), 4):
    print(*code, sep='', end=' ')