Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    if R - L >= 2019 - 1:
        print(0)
    if R % 2019 <= L % 2019:
        print(0)
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    if R - L >= 2019 - 1:
        print(0)
        return
    if R % 2019 <= L % 2019:
        print(0)
        return
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    #if R - L >= 2019 - 1:
    if R % 2019 < L % 2019:
        print(0)
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    if R - L >= 2019 - 1:
        print(0)
        return
    if R % 2019 <= L % 2019:
        print(0)
        return
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    if R - L >= 2019 - 1:
        print(0)
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    if R - L >= 2019 - 1:
        print(0)
        return
    if R % 2019 <= L % 2019:
        print(0)
        return
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    if R - L >= 2019 - 1:
        print(0)
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R+1):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys

MOD = 2019  # type: int

def solve(L: int, R: int):
    if R - L >= 2019 - 1:
        print(0)
        return
    if R % 2019 <= L % 2019:
        print(0)
        return
    else:
        L = L % 2019
        R = R % 2019
        
        smallest = 10000000
        for i in range(L, R):
            for j in range(i+1, R+1):
                calc = (i*j)%2019
                if calc < smallest:
                    smallest = calc
    print(smallest)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    L = int(next(tokens))  # type: int
    R = int(next(tokens))  # type: int
    solve(L, R)

if __name__ == '__main__':
    main()