class Solution {
public:
    int uniquePaths(int m, int n) {
        vector<vector<int>> dp(m, vector<int> (n, 0));
        
        for(int i = 0; i < m; i++)
            dp[i][0] = 1;
        
        for(int j = 0; j < n; j++)
            dp[0][j] = 1;

        for(int i = 1; i < m; i++)
            for(int j = 1; j < n; j++) 
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];

        return dp[m-1][n-1];
    }
};

