class Solution {
public:
    int heightChecker(vector<int>& heights) {
        int count = 0;
        int size = heights.size();
        vector<int> expected(heights);
        sort(expected.begin(),expected.end());
        for(int i=0;i<size;i++){
            if(heights[i]!=expected[i]){
                count++;
            }
        }
        return count;
    }
};