#include <iostream>
#include <algorithm>

using namespace std;
int main() {
    int n, q;
    cin >> n >> q;
    cin.ignore();
    string s;
    getline(cin, s);
    while (q--){
        string query;
        cin >> query;
        if (query == "pop_back") {
            if (n!=0) {
                s.pop_back();
                n--;
            }
        }
        else if (query == "front") {
            if (n!=0)
            cout << s[0] << endl;
        }
        else if (query == "back") {
            if (n!=0)
            cout << s[n-1] << endl;
        }
        else if (query == "sort") {
            int x, y;
            cin >> x >> y;
            sort(s.begin()+x-1, s.begin()+y);
        }
        else if (query == "reverse") {
            int x, y;
            cin >> x >> y;
            reverse(s.begin()+x-1, s.begin()+y);
        }
        else if (query == "print") {
            int x;
            cin >> x;
            cout << s[x-1] << endl;
        }
        else if (query == "substr") {
            int x, y;
            cin >> x >> y;
            if (x<=y)
            cout << s.substr(x-1, y-x+1) << endl;
        }
        else if (query == "push_back") {
            char x;
            cin >> x;
            s.push_back(x);
            n++;
        }
    }
    return 0;
}