```
public class Solution {
public int minPathSum(int[][] grid) {
if (grid == null || grid.length == 0) {
return -1;
}
int m = grid.length;
int n = grid[0].length;
int[][] path = new int[m][n];
path[0][0] = grid[0][0];
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
if (i == 0 && j > 0) {
path[i][j] = grid[i][j] + path[i][j - 1];
} else if (j == 0 && i > 0) {
path[i][j] = grid[i][j] + path[i - 1][j];
} else if (i > 0 && j > 0) {
path[i][j] = grid[i][j] + Math.min(path[i - 1][j], path[i][j - 1]);
}
}
}
return path[m - 1][n - 1];
}
}
```