```
public class Solution {
public List<Integer> getRow(int rowIndex) {
List row = new ArrayList<Integer>();
int index = 0;
while(index < rowIndex){
row.add(0, 1);
for(int j = 1; j < row.size()-1; j++){
row.set(j, row.get(j)+row.get(j+1));
}
index++;
}
return row;
}
}
```

Got and error say "error: bad operand types for binary operator '+'", for the line with "row.set(....)"

Really don't understand.