class Solution {
public:
    int getMaxValue(vector<vector<int>>& grid) {
        int n = grid.size(),m = grid[0].size();
        vector<vector<int>> dp(n+1,vector<int>(m+1));
        for(int i = 1;i <= n;++i)
            for(int j = 1;j <= m;++j)
                dp[i][j] = max(dp[i-1][j],dp[i][j-1]) + grid[i-1][j-1]; //注意，下标是从1开始所以要-1
        return dp[n][m];
    }
};