codeflash-internal/experiments/pie_test_set/p02555.py

24 lines
400 B
Python

def problem_p02555(input_data):
from math import factorial as fac
S = int(eval(input_data))
ans = 0
if S == 1 or S == 2:
return 0
elif S == 3:
return 1
else:
for k in range(1, S):
if S - 2 * k - 1 >= 0 and S - 3 * k >= 0:
ans += fac(S - 2 * k - 1) // (fac(k - 1) * fac(S - 3 * k))
return ans % 1000000007