class Solution(object):
def minPathSum(self, grid):
"""
:type grid: List[List[int]]
:rtype: int
"""
Lenx=len(grid)
if Lenx==0:return 0
Leny=len(grid[0])
for i in range(1,Lenx):
grid[i][0]+=grid[i-1][0]
for i in range(1,Leny):
grid[0][i]+=grid[0][i-1]
for i in range(1,Lenx):
for j in range(1,Leny):
grid[i][j]=min(grid[i][j]+grid[i-1][j],grid[i][j]+grid[i][j-1])
return grid[Lenx-1][Leny-1]