Buggy python submission (verdict: Runtime Error):
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from operator import mul
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    mod = 1000000007

    def modcmb(n, r, mod):
        if r < 0 or r > n:
            return 0
        r = min(r, n - r)
        over = reduce(lambda v1, v2: (v1 * v2) % mod, range(n, n-r, -1))
        under = reduce(lambda v1, v2: (v1 * v2) % mod, range(1, r+1))
        return over * pow(under, mod - 2, mod) % mod

    n, a, b = map(int, input().split())

    count = pow(2, n, mod) - 1
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    if count < 0:
        count += mod * (-count // mod + 1)
    print(count % mod)


main()


Fixed submission:
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from operator import mul
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    def modcmb(n, r, mod):
        if r < 0 or r > n:
            return 0
        r = min(r, n - r)
        over = 1
        under = 1
        for i in range(r):
            over = over * (n - i) % mod
            under = under * (i + 1) % mod

#        over = reduce(lambda v1, v2: (v1 * v2) % mod, range(n, n-r, -1))
#        under = reduce(lambda v1, v2: (v1 * v2) % mod, range(1, r+1))
        return (over * pow(under, mod - 2, mod)) % mod

    mod = 1000000007
    n, a, b = map(int, input().split())

    count = pow(2, n, mod) - 1
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    while count < 0:
        count += mod
    print(count % mod)


main()

Buggy python submission (verdict: Runtime Error):
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from operator import mul
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    mod = 1000000007

    def modpow(n, k, mod):
        if k == 0:
            return 1
        val = modpow(n, k // 2, mod)
        val = (val * val) % mod
        if k % 2 != 0:
            val *= n
        return val

    def modcmb(n, r, mod):
        if r < 0 or r > n:
            return 0
        r = min(r, n - r)
        over = reduce(lambda v1, v2: (v1 * v2) % mod, range(n, n-r, -1))
        under = reduce(lambda v1, v2: (v1 * v2) % mod, range(1, r+1))
        return over * modpow(under, mod - 2, mod) % mod

    n, a, b = map(int, input().split())

    count = modpow(2, n, mod) - 1
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    if count < 0:
        count += mod * (-count // mod + 1)
    print(count % mod)


main()


Fixed submission:
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from operator import mul
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    def modcmb(n, r, mod):
        if r < 0 or r > n:
            return 0
        r = min(r, n - r)
        over = 1
        under = 1
        for i in range(r):
            over = over * (n - i) % mod
            under = under * (i + 1) % mod

#        over = reduce(lambda v1, v2: (v1 * v2) % mod, range(n, n-r, -1))
#        under = reduce(lambda v1, v2: (v1 * v2) % mod, range(1, r+1))
        return (over * pow(under, mod - 2, mod)) % mod

    mod = 1000000007
    n, a, b = map(int, input().split())

    count = pow(2, n, mod) - 1
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    while count < 0:
        count += mod
    print(count % mod)


main()

Buggy python submission (verdict: Runtime Error):
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from operator import mul
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    mod = 1000000007

    def modpow(n, k, mod):
        if k == 0:
            return 1
        val = modpow(n, k // 2, mod)
        val = (val * val) % mod
        if k % 2 != 0:
            val *= n
        return val

    def modcmb(n, r, mod):
        if (r < 0 or r > n):
            return 0
        r = min(r, n - r)
        over = reduce(lambda v1, v2: v1 * v2 % mod, range(n, n-r, -1))
        under = reduce(lambda v1, v2: v1 * v2 % mod, range(1, r+1))
        return over * modpow(under, mod - 2, mod) % mod

    n, a, b = map(int, input().split())

    count = modpow(2, n, mod) - 1
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    while count < 0:
        count += mod

    print(count % mod)


main()


Fixed submission:
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from operator import mul
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    def modcmb(n, r, mod):
        if r < 0 or r > n:
            return 0
        r = min(r, n - r)
        over = 1
        under = 1
        for i in range(r):
            over = over * (n - i) % mod
            under = under * (i + 1) % mod

#        over = reduce(lambda v1, v2: (v1 * v2) % mod, range(n, n-r, -1))
#        under = reduce(lambda v1, v2: (v1 * v2) % mod, range(1, r+1))
        return (over * pow(under, mod - 2, mod)) % mod

    mod = 1000000007
    n, a, b = map(int, input().split())

    count = pow(2, n, mod) - 1
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    while count < 0:
        count += mod
    print(count % mod)


main()

Buggy python submission (verdict: Runtime Error):
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    mod = 1000000007

    def modpow(n, k, mod):
        if k == 0:
            return 1
        val = modpow(n, k // 2, mod)
        val = (val * val) % mod
        if k % 2 != 0:
            val *= n
        return val

    def modcmb(n, r, mod):
        if (r < 0 or r > n):
            return 0
        r = min(r, n - r)
        over = reduce(lambda v1, v2: v1 * v2 % mod, range(n, n-r, -1))
        under = reduce(lambda v1, v2: v1 * v2 % mod, range(1, r+1))
        return over * modpow(under, mod - 2, mod) % mod

    n, a, b = map(int, input().split())

    count = modpow(2, n, mod)
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    while count < 0:
        count += mod

    print(count % mod)


main()


Fixed submission:
# from math import sqrt
# from heapq import heappush, heappop
# from collections import deque
from operator import mul
from functools import reduce
# a, b = [int(v) for v in input().split()]


def main():

    def modcmb(n, r, mod):
        if r < 0 or r > n:
            return 0
        r = min(r, n - r)
        over = 1
        under = 1
        for i in range(r):
            over = over * (n - i) % mod
            under = under * (i + 1) % mod

#        over = reduce(lambda v1, v2: (v1 * v2) % mod, range(n, n-r, -1))
#        under = reduce(lambda v1, v2: (v1 * v2) % mod, range(1, r+1))
        return (over * pow(under, mod - 2, mod)) % mod

    mod = 1000000007
    n, a, b = map(int, input().split())

    count = pow(2, n, mod) - 1
    count -= modcmb(n, a, mod)
    count -= modcmb(n, b, mod)

    while count < 0:
        count += mod
    print(count % mod)


main()