1
class Solution:
2
    def uniquePaths(self, m, n):
3
        dp = [[1] * n for i in range(m)]
4
        for i, j in product(range(1, m), range(1, n)):
5
            dp[i][j] = dp[i - 1][j] + dp[i][j - 1]
6
        return dp[-1][-1]