class Solution:
    def maxValue(self, grid: List[List[int]]) -> int:
        m, n = len(grid), len(grid[0])
        dp = [[0] * n for i in grid]
        dp[0][0] = grid[0][0]
        for i in range(1, m):
            dp[i][0] = dp[i-1][0] + grid[i][0]
        for i in range(1, n):
            dp[0][i] = dp[0][i-1] + grid[0][i]
        for i in range(1, m):
            for j in range(1, n):
                dp[i][j] = max(dp[i-1][j], dp[i][j-1]) + grid[i][j]
        return dp[-1][-1]

class Solution:
    def maxValue(self, grid: List[List[int]]) -> int:
        m, n = len(grid), len(grid[0])
        for i in range(1, m):
            grid[i][0] += grid[i-1][0]
        for i in range(1, n):
            grid[0][i] += grid[0][i-1]
        for i in range(1, m):
            for j in range(1, n):
                grid[i][j] += max(grid[i][j-1], grid[i-1][j])
        return grid[-1][-1]