#include <bits/stdc++.h>
#define IOS std::ios::sync_with_stdio(0)
#define C std::cin.tie(0)
#define Co std::cout.tie(0)

typedef long long LL;
LL c, Q;
std::vector <LL> q;
int main() {
	IOS; C; Co;
	std::cin >> c >> Q;
	while (Q--) {
		LL op;
		std::cin >> op;
		if (op != 4) {
			if (op == 1) {
				LL x;
				std::cin >> x;
				for (LL i = 1; i <= x; ++i) q.push_back(i);
			}
			if (op == 2) {
				LL y;
				std::cin >> y;
				if (q.size() >= y) q.erase(q.begin(), q.begin() + y);
				else q.clear();
			}
			if (op == 3){
				LL z;
				std::cin >> z;
				if (z - 1 < q.size()) std::cout << q[z - 1] << '\n';
			}
		}
		else {
			auto maxn = std::max_element(q.begin(), q.end());
			std::cout << *maxn << '\n';
		}
	}
	return 0;
}