#include<cstdio>
#include<vector>
#include<algorithm>
#include<utility>
#include<numeric>
#include<iostream>
#include<array>
#include<string>
#include<sstream>
#include<stack>
#include<queue>
#include<list>
#include<functional>
#define _USE_MATH_DEFINES

#include<math.h>
#include<map>

#define SENTINEL 1000000001

#define min(a,b) (a)>(b)?(b):(a)
#define max(a,b) (a)>(b)?(a):(b)

using namespace std;

typedef pair<int, int> pii;

long long seg[262149], n, v, a, b, c, d, INF = (1LL << 31) - 1, size_ = 1;
void update(long long p, long long q, long long r, long long s, long long t, long long u, long long v) {
	if (s <= p || q <= r) { if (v != INF)seg[u] = v; return; }
	if (p <= r && s <= q) { seg[u] = t; return; }
	long long w = v; if (w == INF)w = seg[u]; seg[u] = INF;
	update(p, q, r, (r + s) / 2, t, u * 2, w);
	update(p, q, (r + s) / 2, s, t, u * 2 + 1, w);
}
long long find(long long p, long long q, long long r, long long s, long long u) {
	if (s <= p || q <= r)return INF;
	if ((r <= p && q <= s) && (seg[u] != INF || s - r == 1)) { return seg[u]; }
	long long a1 = find(p, q, r, (r + s) / 2, u * 2);
	long long a2 = find(p, q, (r + s) / 2, s, u * 2 + 1);
	return min(a1, a2);
}
int main() {
	cin >> n >> v; while (size_ < n)size_ *= 2;
	for (int i = 1; i <= size_ * 2; i++)seg[i] = INF;
	for (int i = 1; i <= v; i++) {
		scanf("%d", &a);
		if (a == 0) { scanf("%lld%lld%lld", &b, &c, &d); c++; update(b, c, 0, size_, d, 1, INF); }
		if (a == 1) { scanf("%lld", &b); printf("%lld\n", find(b, b + 1, 0, size_, 1)); }
	}
	return 0;
}
