Buggy python submission (verdict: Time Limit Exceeded):
def main():
    s = input()
    MOD = 2019
    r = [0]*MOD
    r[0] = 1
    z = 0
    t = 1
    for i in reversed(s):
        z = int(i) * t%MOD + z
        z %= MOD
        t *= 10
        r[z] += 1
    print(sum(i*(i-1)//2 for i in r))


if __name__ == '__main__':
    main()


Fixed submission:
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
z = 0
j = 1
for i in range(0,n):
    j = j * 10 % m
    ss = int(s[n-i-1])*j + z
    z = ss%m



    a += r[z]
    r[z] += 1

print(a)

Buggy python submission (verdict: Runtime Error):
s = input()
MOD = 2019
r = [0]*MOD
r[0] = 1
z = 0
t = 0
for i in reversed(s):
    z = int(i) * pow(10,t,m) + z
    z %= MOD
    r[z] += 1
    t += 1
print(sum(i*(i-1)//2 for i in r))


Fixed submission:
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
z = 0
j = 1
for i in range(0,n):
    j = j * 10 % m
    ss = int(s[n-i-1])*j + z
    z = ss%m



    a += r[z]
    r[z] += 1

print(a)

Buggy python submission (verdict: Runtime Error):
s = input()
n = len(s)
m = 2019
a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
for i in range(0,n):
    z = (int(s[n-i-1])*pow(10,i,m) + z)%m
    a += r[z]
    r[z] += 1
print(a)


Fixed submission:
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
z = 0
j = 1
for i in range(0,n):
    j = j * 10 % m
    ss = int(s[n-i-1])*j + z
    z = ss%m



    a += r[z]
    r[z] += 1

print(a)

Buggy python submission (verdict: Time Limit Exceeded):
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
for i in range(n):
    z = int(s[i:])%m
    a += r[z]
    r[z] += 1

print(a)


Fixed submission:
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
z = 0
j = 1
for i in range(0,n):
    j = j * 10 % m
    ss = int(s[n-i-1])*j + z
    z = ss%m



    a += r[z]
    r[z] += 1

print(a)

Buggy python submission (verdict: Time Limit Exceeded):
s = input()
n = len(s)
m = 2019

r = [0 for _ in range(m+1)]
r[0] = 1
for i in range(n):
    z = int(s[i:])%m
    r[z] += 1
a = 0
for i in range(m+1):
    a += r[i]*(r[i]-1)//2

print(a)


Fixed submission:
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
z = 0
j = 1
for i in range(0,n):
    j = j * 10 % m
    ss = int(s[n-i-1])*j + z
    z = ss%m



    a += r[z]
    r[z] += 1

print(a)

Buggy python submission (verdict: Time Limit Exceeded):
s = input()
n = len(s)
m = 673

w = [[] for _ in range(3)]
ans = 0

for i in range(n):
    z = int(s[i:])%3
    w[z].append(i)

for i in range(3):
    for j in range(len(w[i])):
            for k in range(j,len(w[i])):
                u = w[i][j]
                v = w[i][k]
                if u == v :
                    y = int(s[u:])
                else:
                    y = int(s[u:v])
                if int(y)%m == 0:
                    ans += 1
print(ans)


Fixed submission:
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
z = 0
j = 1
for i in range(0,n):
    j = j * 10 % m
    ss = int(s[n-i-1])*j + z
    z = ss%m



    a += r[z]
    r[z] += 1

print(a)

Buggy python submission (verdict: Time Limit Exceeded):
s = input()
n = len(s)
m = 2019

ans = 0

for i in range(n-1):
    for j in range(i+1,n+1):
        x = int(s[i:j])
        if x%m == 0:
            ans += 1
print(ans)


Fixed submission:
s = input()
n = len(s)
m = 2019

a = 0
r = [0 for _ in range(m+1)]
r[0] = 1
z = 0
j = 1
for i in range(0,n):
    j = j * 10 % m
    ss = int(s[n-i-1])*j + z
    z = ss%m



    a += r[z]
    r[z] += 1

print(a)