codeflash-internal/experiments/pie_test_set/p02625.py

12 lines
274 B
Python

def problem_p02625(input_data):
n, m = list(map(int, input_data.split()))
a, M, d = 1, 10**9 + 7, [1]
for i in range(1, n + 1):
d.append(((m - n + i - 1) * d[i - 1] + (i - 1) * d[i - 2]) % M)
a = a * (m - i + 1) % M
return a * d[-1] % M