class Solution {
public int uniquePathsWithObstacles(int[][] obstacleGrid) {
int m=obstacleGrid.length;
int n=obstacleGrid[0].length;
int[][] res=new int[m][n];
for(int i=0;i<m;i++){
if(obstacleGrid[i][0]==1){
break;
}
res[i][0]=1;
}
for(int i=0;i<n;i++){
if(obstacleGrid[0][i]==1){
break;
}
res[0][i]=1;
}
for(int i=1;i<m;i++){
for(int j=1;j<n;j++){
if(obstacleGrid[i][j]==1){
res[i][j]=0;
}else{
res[i][j]=res[i-1][j]+res[i][j-1];
}
}
}
return res[m-1][n-1];
}
}