Buggy python submission (verdict: Time Limit Exceeded):
import sys

input = sys.stdin.readline

L, R = map(int, input().split())

def main():
    if R // 2019 != L // 2019:
        ans = 0
    else:
        # ansLi = L % 2019
        # ansLj = (L+1) % 2019
        # ansL = ansLi * ansLj

        # ansRi = R % 2019
        # ansRj = (R-1) % 2019
        # ansR = ansRi * ansRj
        ansL = L*(L+1) % 2019
        ansR = R*(R-1) % 2019

        ans = min(ansL, ansR)

    return int(ans)

# print(main())

def search_all():
    if R // 2019 != L // 2019:
        ans = 0
    ans = float("inf")
    for i in range(L, R):
        for j in range(i+1, R+1):
            ans = min(i*j % 2019, ans)
            if ans == 0:
                break
    return ans

print(search_all())

Fixed submission:
import sys

input = sys.stdin.readline

L, R = map(int, input().split())

def main():
    if R // 2019 != L // 2019:
        ans = 0
    else:
        # ansLi = L % 2019
        # ansLj = (L+1) % 2019
        # ansL = ansLi * ansLj

        # ansRi = R % 2019
        # ansRj = (R-1) % 2019
        # ansR = ansRi * ansRj
        ansL = L*(L+1) % 2019
        ansR = R*(R-1) % 2019

        ans = min(ansL, ansR)

    return int(ans)

# print(main())

def search_all():
    if R // 2019 != L // 2019:
        return 0
    ans = float("inf")
    for i in range(L, R):
        for j in range(i+1, R+1):
            ans = min(i*j % 2019, ans)
            if ans == 0:
                break
    return ans

print(search_all())

Buggy python submission (verdict: Time Limit Exceeded):
import sys

input = sys.stdin.readline

L, R = map(int, input().split())

def main():
    if R // 2019 != L // 2019:
        ans = 0
    else:
        # ansLi = L % 2019
        # ansLj = (L+1) % 2019
        # ansL = ansLi * ansLj

        # ansRi = R % 2019
        # ansRj = (R-1) % 2019
        # ansR = ansRi * ansRj
        ansL = L*(L+1) % 2019
        ansR = R*(R-1) % 2019

        ans = min(ansL, ansR)

    return int(ans)

# print(main())

def search_all():
    if L - R >= 2019:
        return 0
    ans = float("inf")
    for i in range(L, R):
        for j in range(i+1, R+1):
            ans = min(i*j % 2019, ans)
    return ans

print(search_all())

Fixed submission:
import sys

input = sys.stdin.readline

L, R = map(int, input().split())

def main():
    if R // 2019 != L // 2019:
        ans = 0
    else:
        # ansLi = L % 2019
        # ansLj = (L+1) % 2019
        # ansL = ansLi * ansLj

        # ansRi = R % 2019
        # ansRj = (R-1) % 2019
        # ansR = ansRi * ansRj
        ansL = L*(L+1) % 2019
        ansR = R*(R-1) % 2019

        ans = min(ansL, ansR)

    return int(ans)

# print(main())

def search_all():
    if R // 2019 != L // 2019:
        return 0
    ans = float("inf")
    for i in range(L, R):
        for j in range(i+1, R+1):
            ans = min(i*j % 2019, ans)
            if ans == 0:
                break
    return ans

print(search_all())

Buggy python submission (verdict: Runtime Error):
import sys

input = sys.stdin.readline

L, R = map(int, input().split())

def main():
    LR = list(range(L, R+1))
    N = len(LR)
    if N >= 2019:
        ans = 0
    else:
        ansLi = LR[0] % 2019
        ansLj = LR[1] % 2019
        ansL = ansLi * ansLj

        ansRi = LR[-1] % 2019
        ansRj = LR[-2] % 2019
        ansR = ansRi * ansRj

        ans = min(ansL, ansR)

    return ans

print(main())

Fixed submission:
import sys

input = sys.stdin.readline

L, R = map(int, input().split())

def main():
    if R // 2019 != L // 2019:
        ans = 0
    else:
        # ansLi = L % 2019
        # ansLj = (L+1) % 2019
        # ansL = ansLi * ansLj

        # ansRi = R % 2019
        # ansRj = (R-1) % 2019
        # ansR = ansRi * ansRj
        ansL = L*(L+1) % 2019
        ansR = R*(R-1) % 2019

        ans = min(ansL, ansR)

    return int(ans)

# print(main())

def search_all():
    if R // 2019 != L // 2019:
        return 0
    ans = float("inf")
    for i in range(L, R):
        for j in range(i+1, R+1):
            ans = min(i*j % 2019, ans)
            if ans == 0:
                break
    return ans

print(search_all())

Buggy python submission (verdict: Runtime Error):
import sys
import bisect

input = sys.stdin.readline

L, R = map(int, input().split())

LR = list(range(L, R+1))
N = len(LR)
index = bisect.bisect_left(LR, 2019)
if index == 0:
    i, j = LR[0], LR[1]
elif index == N:
    i, j = LR[-2], LR[-1]
else:
    i, j = LR[index-1], LR[index]

modi = i % 2019
modj = j % 2019
print(modi * modj)

Fixed submission:
import sys

input = sys.stdin.readline

L, R = map(int, input().split())

def main():
    if R // 2019 != L // 2019:
        ans = 0
    else:
        # ansLi = L % 2019
        # ansLj = (L+1) % 2019
        # ansL = ansLi * ansLj

        # ansRi = R % 2019
        # ansRj = (R-1) % 2019
        # ansR = ansRi * ansRj
        ansL = L*(L+1) % 2019
        ansR = R*(R-1) % 2019

        ans = min(ansL, ansR)

    return int(ans)

# print(main())

def search_all():
    if R // 2019 != L // 2019:
        return 0
    ans = float("inf")
    for i in range(L, R):
        for j in range(i+1, R+1):
            ans = min(i*j % 2019, ans)
            if ans == 0:
                break
    return ans

print(search_all())