Buggy python submission (verdict: Time Limit Exceeded):
def main():
    H, W = map(int, input().split())
    N = 80 * (H+W) // 2
    A = [list(map(int, input().split())) for _ in range(H)]
    B = [list(map(int, input().split())) for _ in range(H)]
    dp = [[set() for _ in range(W+1)] for _ in range(2)]
    dp[0][1].add(0)
    def ltN(x): return x <= N
    for i in range(H):
        dp[(i+1) & 1] = [set() for _ in range(W+1)]
        for j in range(W):
            diff = abs(A[i][j] - B[i][j])
            dp[(i+1) & 1][j+1] |= set(filter(ltN, [abs(x + diff)
                                                   for x in dp[i & 1][j+1]]))
            dp[(i+1) & 1][j+1] |= set(filter(ltN, [abs(x - diff)
                                                   for x in dp[i & 1][j+1]]))
            dp[(i+1) & 1][j+1] |= set(filter(ltN, [abs(x + diff)
                                                   for x in dp[(i+1) & 1][j]]))
            dp[(i+1) & 1][j+1] |= set(filter(ltN, [abs(x - diff)
                                                   for x in dp[(i+1) & 1][j]]))
    print(min(dp[H & 1][W]))


if __name__ == "__main__":
    main()


Fixed submission:
def main():
    H, W = map(int, input().split())
    N = 80 * (H+W) // 2
    A = [list(map(int, input().split())) for _ in range(H)]
    B = [list(map(int, input().split())) for _ in range(H)]
    dp = [[set() for _ in range(W+1)] for _ in range(2)]
    dp[0][1].add(0)
    def ltN(x): return x <= N
    for i in range(H):
        dp[(i+1) & 1] = [set() for _ in range(W+1)]
        for j in range(W):
            diff = abs(A[i][j] - B[i][j])
            tmp = set()
            for x in dp[i & 1][j + 1]:
                tmp.add(abs(x + diff))
                tmp.add(abs(x - diff))
            for x in dp[(i+1) & 1][j]:
                tmp.add(abs(x + diff))
                tmp.add(abs(x - diff))
            dp[(i+1) & 1][j+1] = tmp
    print(min(dp[H & 1][W]))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    H, W = map(int, input().split())
    N = 80 * (H+W) // 2 + 1
    A = [list(map(int, input().split())) for _ in range(H)]
    B = [list(map(int, input().split())) for _ in range(H)]
    dp = [[[False] * N for _ in range(W+1)] for _ in range(2)]
    dp[0][1][0] = True
    for i in range(H):
        dp[(i+1) & 1] = [[False] * N for _ in range(W+1)]
        for j in range(W):
            diff = abs(A[i][j] - B[i][j])
            for k in range(N):
                dp[(i+1) & 1][j+1][abs(k - diff)] |= dp[i & 1][j+1][k]
                dp[(i+1) & 1][j+1][abs(k - diff)] |= dp[(i+1) & 1][j][k]
                if k + diff < N:
                    dp[(i+1) & 1][j+1][k + diff] |= dp[i & 1][j+1][k]
                    dp[(i+1) & 1][j+1][k + diff] |= dp[(i+1) & 1][j][k]
    print(dp[H & 1][W].index(True))


if __name__ == "__main__":
    main()


Fixed submission:
def main():
    H, W = map(int, input().split())
    N = 80 * (H+W) // 2
    A = [list(map(int, input().split())) for _ in range(H)]
    B = [list(map(int, input().split())) for _ in range(H)]
    dp = [[set() for _ in range(W+1)] for _ in range(2)]
    dp[0][1].add(0)
    def ltN(x): return x <= N
    for i in range(H):
        dp[(i+1) & 1] = [set() for _ in range(W+1)]
        for j in range(W):
            diff = abs(A[i][j] - B[i][j])
            tmp = set()
            for x in dp[i & 1][j + 1]:
                tmp.add(abs(x + diff))
                tmp.add(abs(x - diff))
            for x in dp[(i+1) & 1][j]:
                tmp.add(abs(x + diff))
                tmp.add(abs(x - diff))
            dp[(i+1) & 1][j+1] = tmp
    print(min(dp[H & 1][W]))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    H, W = map(int, input().split())
    A = [list(map(int, input().split())) for _ in range(H)]
    B = [list(map(int, input().split())) for _ in range(H)]
    dp = [[set() for _ in range(W+1)] for _ in range(H+1)]
    dp[1][1].add(abs(A[0][0] - B[0][0]))
    for i in range(H):
        for j in range(W):
            diff = abs(A[i][j] - B[i][j])
            dp[i+1][j+1] |= set(map(lambda x: abs(x + diff), dp[i][j+1]))
            dp[i+1][j+1] |= set(map(lambda x: abs(x - diff), dp[i][j+1]))
            dp[i+1][j+1] |= set(map(lambda x: abs(x + diff), dp[i+1][j]))
            dp[i+1][j+1] |= set(map(lambda x: abs(x - diff), dp[i+1][j]))
    print(min(dp[H][W]))


if __name__ == "__main__":
    main()


Fixed submission:
def main():
    H, W = map(int, input().split())
    N = 80 * (H+W) // 2
    A = [list(map(int, input().split())) for _ in range(H)]
    B = [list(map(int, input().split())) for _ in range(H)]
    dp = [[set() for _ in range(W+1)] for _ in range(2)]
    dp[0][1].add(0)
    def ltN(x): return x <= N
    for i in range(H):
        dp[(i+1) & 1] = [set() for _ in range(W+1)]
        for j in range(W):
            diff = abs(A[i][j] - B[i][j])
            tmp = set()
            for x in dp[i & 1][j + 1]:
                tmp.add(abs(x + diff))
                tmp.add(abs(x - diff))
            for x in dp[(i+1) & 1][j]:
                tmp.add(abs(x + diff))
                tmp.add(abs(x - diff))
            dp[(i+1) & 1][j+1] = tmp
    print(min(dp[H & 1][W]))


if __name__ == "__main__":
    main()