class Solution {
public:
    string reverseLeftWords(string s, int n) {
        string temp;
        temp = s.substr(0,n);
        s.erase(0,n);
        s.insert(s.size(),temp);
        return s;
    }
};

class Solution {
public:
    string reverseLeftWords(string s, int n) {
        reverse(s.begin(), s.begin() + n);
        reverse(s.begin() + n, s.end());
        reverse(s.begin(), s.end());
        return s;
    }
};