class Solution {

public:

int uniquePaths(int m, int n) {

```
vector<vector<int>> box(m,vector<int>(n,1));
for (int i = 1; i < m; ++i){
for (int j = 1; j < n; ++j){
box[i][j] = box[i-1][j]+box[i][j-1];
}
}
return box[m-1][n-1];
}
```

};