#include <iostream>
#include <vector>
#include <boost/container/flat_set.hpp>
using namespace std;
using boost::container::flat_set;

int main() {
    int n, m;
    cin >> n >> m;
    vector<int> a(n);
    for (int i = 0; i < n; ++i) cin >> a[i];
    for (int i = 0; i < m; ++i) {
        int t, l, r;
        cin >> t >> l >> r;
        if (t == 1) {
            int x, y;
            cin >> x >> y;
            for (int j = l; j <= r; ++j) {
                if (a[j] == x) a[j] = y;
            }
        } else {
            int k;
            cin >> k;
            flat_set<int> b(a.begin(), a.end()); // ソート済み重複なし
            int s = 0;
            for (int c : b) {
                if (k + s < c) {
                    cout << k + s << endl;
                    goto NEXT;
                }
                s++;
            }
            cout << k + s << endl;
            NEXT:;
        }
    }
    return 0;
}