public class Solution {

```
public int uniquePaths(int m, int n) {
int[][] D = new int[m][n];
for(int i = 0; i < m; i++){
D[i][0] = 1;
}
for(int j = 0; j < n; j++){
D[0][j] = 1;
}
for(int i = 1; i < m; i++){
for(int j = 1; j < n; j++){
D[i][j] = D[i - 1][j] + D[i][j - 1];
}
}
return D[m-1][n-1];
}
```

}