class Solution {
    public int uniquePaths(int m, int n) {
        
        if (m ==0||n ==0){
            return 0;
        }
        
        int dp [][] = new int[m][n];
        
        //first row scenario
        for(int i = 0;i<n; i++)
        {
            
            dp[0][i] = 1;
        }
        
        for(int i =0; i<m; i++){
            
            dp[i][0]=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];
    }
}