Buggy python submission (verdict: Time Limit Exceeded):
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + 10 ** i * int(x) % 2019
 #   print(tmp % 2019)
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
print(int(ans))

Fixed submission:
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + pow(10, i , 2019) * int(x) 
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
print(int(ans))

Buggy python submission (verdict: Time Limit Exceeded):
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + 10 ** i * int(x) % 2019
 #   print(tmp % 2019)
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
#print(L,c)
print(int(ans))

Fixed submission:
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + pow(10, i , 2019) * int(x) 
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
print(int(ans))

Buggy python submission (verdict: Runtime Error):
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + 10 ** i * int(x) % 2019
 #   print(tmp % 2019)
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  return n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
#print(L,c)
print(int(ans))

Fixed submission:
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + pow(10, i , 2019) * int(x) 
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
print(int(ans))

Buggy python submission (verdict: Runtime Error):
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + 10 ** i * int(x) % 2019
 #   print(tmp % 2019)
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  return n * (n - 1) // 
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
#print(L,c)
print(int(ans))

Fixed submission:
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + pow(10, i , 2019) * int(x) 
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
print(int(ans))

Buggy python submission (verdict: Time Limit Exceeded):
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + 10 ** i * int(x) % 2019
 #   print(tmp % 2019)
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  factorial(n) / factorial(r) / factorial(n - r)
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
#print(L,c)
print(int(ans))

Fixed submission:
S = input()
S = S[::-1]
L = [0]
i = 0
for x in S:
    tmp = L[-1] + pow(10, i , 2019) * int(x) 
    L.append(tmp % 2019)
    i += 1
L = sorted(L[1::])
def counter(array):
    from collections import Counter
    return list(Counter(array).most_common())
c = counter(L)
from math import factorial
def comb(n,r):
    if n == 1: return 0
    return  n * (n - 1) // 2
ans = 0
for x in c:
    if x[0] == 0: ans += x[1]
    ans += comb(x[1],2)
print(int(ans))