Buggy python submission (verdict: Runtime Error):
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    C = math.factorial(n) // (math.factorial(n - r) * math.factorial(r))
    return C

if n <= 1 and m >= 2:
    print(combinations_count(m, 2))
    sys.exit()
elif n >= 2 and m <= 1@:
    print(combinations_count(n, 2))
    sys.exit()
elif n == m == 1:
    print(1)
    sys.exit()
elif n == m == 0:
    print(0)
    sys.exit()
else:
    print(combinations_count(n, 2) + combinations_count(m, 2))

Fixed submission:
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    C = math.factorial(n) // (math.factorial(n - r) * math.factorial(r))
    return C

if n <= 1 and m >= 2:
    print(combinations_count(m, 2))
    sys.exit()
elif n >= 2 and m <= 1:
    print(combinations_count(n, 2))
    sys.exit()
elif n == m == 1:
    print(0)
    sys.exit()
elif n == m == 0:
    print(0)
    sys.exit()
else:
    print(combinations_count(n, 2) + combinations_count(m, 2))

Buggy python submission (verdict: Runtime Error):
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    C = math.factorial(n) // (math.factorial(n - r) * math.factorial(r))
    return C

if n == 0 and m >= 2:
    print(combinations_count(m, 2))
    sys.exit()
elif n >= 2 and m == 0:
    print(combinations_count(n, 2))
    sys.exit()
elif n == m == 1:
    print(1)
    sys.exit()
elif n == m == 0:
    print(0)
    sys.exit()
else:
    print(combinations_count(n, 2) + combinations_count(m, 2))

Fixed submission:
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    C = math.factorial(n) // (math.factorial(n - r) * math.factorial(r))
    return C

if n <= 1 and m >= 2:
    print(combinations_count(m, 2))
    sys.exit()
elif n >= 2 and m <= 1:
    print(combinations_count(n, 2))
    sys.exit()
elif n == m == 1:
    print(0)
    sys.exit()
elif n == m == 0:
    print(0)
    sys.exit()
else:
    print(combinations_count(n, 2) + combinations_count(m, 2))

Buggy python submission (verdict: Runtime Error):
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    return math.factorial(n) // (math.factorial(n - r) * math.factorial(r))

if n == 0 and m <= 2:
    print(combinations_count(m, 2))
    sys.exit()
elif n <= 2 and m == 0:
    print(combinations_count(n, 2))
    sys.exit()
elif n == m == 1:
    print(1)
    sys.exit()
else:
    print(combinations_count(n, 2) + combinations_count(m, 2))

Fixed submission:
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    C = math.factorial(n) // (math.factorial(n - r) * math.factorial(r))
    return C

if n <= 1 and m >= 2:
    print(combinations_count(m, 2))
    sys.exit()
elif n >= 2 and m <= 1:
    print(combinations_count(n, 2))
    sys.exit()
elif n == m == 1:
    print(0)
    sys.exit()
elif n == m == 0:
    print(0)
    sys.exit()
else:
    print(combinations_count(n, 2) + combinations_count(m, 2))

Buggy python submission (verdict: Runtime Error):
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    return math.factorial(n) // (math.factorial(n - r) * math.factorial(r))

print(combinations_count(n, 2) + combinations_count(m, 2))

Fixed submission:
import math
import sys
n, m = map(int, input().split())

def combinations_count(n, r):
    C = math.factorial(n) // (math.factorial(n - r) * math.factorial(r))
    return C

if n <= 1 and m >= 2:
    print(combinations_count(m, 2))
    sys.exit()
elif n >= 2 and m <= 1:
    print(combinations_count(n, 2))
    sys.exit()
elif n == m == 1:
    print(0)
    sys.exit()
elif n == m == 0:
    print(0)
    sys.exit()
else:
    print(combinations_count(n, 2) + combinations_count(m, 2))