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

def solve():
    input = sys.stdin.readline
    H, W = map(int, input().split())
    grid = dict() #絶対値
    dist = dict()
    for h in range(H):
        grid[h] = dict()
        dist[h] = dict()
        for w in range(W):
            grid[h][w] = 0
            dist[h][w] = set()

    for h in range(H):
        A = [int(a) for a in input().split()]
        for w in range(W):
            grid[h][w] = A[w]
    for h in range(H):
        B = [int(b) for b in input().split()]
        for w in range(W):
            grid[h][w] = abs(grid[h][w] - B[w])
    #print(grid)

    dist[0][0] |= {grid[0][0]}
    for h in range(H):
        for w in range(W):
            for item in dist[h][w]:
                if h < H - 1:
                    n = grid[h+1][w]
                    dist[h+1][w] |= {abs(item + n), abs(item - n)}
                if w < W - 1:
                    n = grid[h][w+1]
                    dist[h][w+1] |= {abs(item + n), abs(item - n)}
    
    ans = 1000000
    for item in dist[H-1][W-1]:
        ans =min(ans, item)
    print(ans)

    return 0

if __name__ == "__main__":
    solve()


Fixed submission:
import sys

def solve():
    input = sys.stdin.readline
    H, W = map(int, input().split())
    grid = dict() #絶対値
    zero = 12800
    dist = dict()
    for h in range(H):
        grid[h] = dict()
        dist[h] = dict()
        for w in range(W):
            grid[h][w] = 0
            dist[h][w] = 0

    for h in range(H):
        for x, v in enumerate(map(int, input().split())):
            grid[h][x] = v
    for h in range(H):
        for x, v in enumerate(map(int, input().split())):
            grid[h][x] = abs(grid[h][x] - v)

    dist[0][0] |= 2 ** zero >> grid[0][0]
    dist[0][0] |= 2 ** zero << grid[0][0]

    for h in range(H):
        for w in range(W):
            if h < H - 1:
                n = grid[h+1][w]
                dist[h+1][w] |= dist[h][w] >> n
                dist[h+1][w] |= dist[h][w] << n
            if w < W - 1:
                n = grid[h][w+1]
                dist[h][w+1] |= dist[h][w] >> n
                dist[h][w+1] |= dist[h][w] << n
    
    ans = 100000000
    for i in range(zero*2):
        if dist[H-1][W-1] & 1:
            ans = min(ans, abs(i - zero))
        dist[H-1][W-1] >>= 1

    print(ans)

    return 0

if __name__ == "__main__":
    solve()

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

def solve():
    input = sys.stdin.readline
    H, W = map(int, input().split())
    grid = dict() #絶対値
    dist = dict()
    for h in range(H):
        grid[h] = dict()
        dist[h] = dict()
        for w in range(W):
            grid[h][w] = 0
            dist[h][w] = set()

    for h in range(H):
        A = [int(a) for a in input().split()]
        for w in range(W):
            grid[h][w] = A[w]
    for h in range(H):
        B = [int(b) for b in input().split()]
        for w in range(W):
            grid[h][w] = abs(grid[h][w] - B[w])
    #print(grid)

    dist[0][0] |= {grid[0][0]}
    for h in range(H):
        for w in range(W):
            for item in dist[h][w]:
                if h < H - 1:
                    n = grid[h+1][w]
                    dist[h+1][w] |= {abs(item + n)}
                    dist[h+1][w] |= {abs(item - n)}
                if w < W - 1:
                    n = grid[h][w+1]
                    dist[h][w+1] |= {abs(item + n)}
                    dist[h][w+1] |= {abs(item - n)}

    #print(dist)
    ans = 1000000
    for item in dist[H-1][W-1]:
        ans = min(ans, item)
    print(ans)

    return 0

if __name__ == "__main__":
    solve()

Fixed submission:
import sys

def solve():
    input = sys.stdin.readline
    H, W = map(int, input().split())
    grid = dict() #絶対値
    zero = 12800
    dist = dict()
    for h in range(H):
        grid[h] = dict()
        dist[h] = dict()
        for w in range(W):
            grid[h][w] = 0
            dist[h][w] = 0

    for h in range(H):
        for x, v in enumerate(map(int, input().split())):
            grid[h][x] = v
    for h in range(H):
        for x, v in enumerate(map(int, input().split())):
            grid[h][x] = abs(grid[h][x] - v)

    dist[0][0] |= 2 ** zero >> grid[0][0]
    dist[0][0] |= 2 ** zero << grid[0][0]

    for h in range(H):
        for w in range(W):
            if h < H - 1:
                n = grid[h+1][w]
                dist[h+1][w] |= dist[h][w] >> n
                dist[h+1][w] |= dist[h][w] << n
            if w < W - 1:
                n = grid[h][w+1]
                dist[h][w+1] |= dist[h][w] >> n
                dist[h][w+1] |= dist[h][w] << n
    
    ans = 100000000
    for i in range(zero*2):
        if dist[H-1][W-1] & 1:
            ans = min(ans, abs(i - zero))
        dist[H-1][W-1] >>= 1

    print(ans)

    return 0

if __name__ == "__main__":
    solve()