[조합]

# 3C2

def comb(cnt, start):
    global N, M
    if cnt == N:
        print(answer)
    return

    for i in range(start, M):
        answer.append(i)
        comb(cnt + 1, i+1)
        answer.pop()

M = 3
N = 2
answer = []

comb(0, 0)