Problem:
Range Update Query (RUQ)

Write a program which manipulates a sequence A = {a0, a1, . . . , an−1} with the following operations:

update(s, t, x): change as, as+1, ..., at to x.

find(i): output the value of ai.

Note that the initial values of ai (i = 0, 1, . . . , n−1) are 231-1.

Input

n q
query1
query2
:
queryq

In the first line, n (the number of elements in A) and q (the number of queries) are given. Then, ith query queryi is given in the following format:

0 s t x

or

1 i

The first digit represents the type of the query. '0' denotes update(s, t, x) and '1' denotes find(i).

Output

For each find operation, print the value.

Constraints

1 ≤ n ≤ 100000

1 ≤ q ≤ 100000

0 ≤ s ≤ t < n

0 ≤ i < n

0 ≤ x < 231−1

Sample Input 1

3 5
0 0 1 1
0 1 2 3
0 2 2 2
1 0
1 1

Sample Output 1

1
3

Sample Input 2

1 3
1 0
0 0 0 5
1 0

Sample Output 2

2147483647
5

Solution in C++14 (judge verdict: Accepted)

////////////////////////////////////////
///  tu3 pro-con template            ///
////////////////////////////////////////
#include <cassert>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <algorithm>
#include <numeric>
#include <functional>
#include <vector>
#include <queue>
#include <string>
#include <complex>
#include <stack>
#include <set>
#include <map>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <regex>
#include <type_traits>
#include <mutex>
#include <array>
using namespace std;

//// MACRO ////
#define countof(a) (sizeof(a)/sizeof(a[0]))

#define REP(i,n) for (int i = 0; i < (n); i++)
#define RREP(i,n) for (int i = (n)-1; i >= 0; i--)
#define FOR(i,s,n) for (int i = (s); i < (n); i++)
#define RFOR(i,s,n) for (int i = (n)-1; i >= (s); i--)
#define pos(c,i) c.being() + (i)
#define allof(c) c.begin(), c.end()
#define aallof(a) a, countof(a)
#define partof(c,i,n) c.begin() + (i), c.begin() + (i) + (n)
#define apartof(a,i,n) a + (i), a + (i) + (n)
typedef unsigned int uint;
typedef long long llong;
typedef unsigned long long ullong;
#define long long long

#define EPS 1e-9
#define INF (1L << 28)
#define LINF (1LL << 60)

#define PREDICATE(t,a,exp) [&](const t & a) -> bool { return exp; }
#define COMPARISON_T(t) bool(*)(const t &, const t &)
#define COMPARISON(t,a,b,exp) [&](const t & a, const t & b) -> bool { return exp; }
#define CONVERTER(TSrc,t,TDest,exp) [&](const TSrc &t)->TDest { return exp; }

#define PRED(a,exp) [&](const auto & a) -> bool { return exp; }
#define COMP(a,b,exp) [&](const auto & a, const auto & b) -> bool { return exp; }
#define CONV2(a,b,exp) [&](const auto & a, const auto & b) -> auto { return exp; }
#define CONV3(a,b,c,exp) [&](const auto & a, const auto & b, const auto & c) -> auto { return exp; }

inline int sign_of(double x) { return abs(x) < EPS ? 0 : x > 0 ? 1 : -1; }
inline bool inRange(int val, int min, int max) { return val >= min && val < max; }
inline bool inRange(double val, double min, double max) { return val - min > -EPS && val - max < EPS; }
inline bool inRange(int x, int y, int W, int H) { return x >= 0 && x < W && y >= 0 && y < H; } // W,H含まない

template <class T> struct vevector : public vector<vector<T>> { vevector(int n = 0, int m = 0, const T &initial = T()) : vector<vector<T>>(n, vector<T>(m, initial)) { } };
template <class T> struct vevevector : public vector<vevector<T>> { vevevector(int n = 0, int m = 0, int l = 0, const T &initial = T()) : vector<vevector<T>>(n, vevector<T>(m, l, initial)) { } };
template <class T> struct vevevevector : public vector<vevevector<T>> { vevevevector(int n = 0, int m = 0, int l = 0, int k = 0, const T &initial = T()) : vector<vevevector<T>>(n, vevevector<T>(m, l, k, initial)) { } };

//// i/o helper ////

namespace std {
	template <class T1, class T2> inline istream & operator >> (istream & in, pair<T1, T2> &p) { in >> p.first >> p.second; return in; }
	template <class T1, class T2> inline ostream & operator << (ostream &out, const pair<T1, T2> &p) { out << p.first << " " << p.second; return out; }
}
template <class T> T read() { T t; cin >> t; return t; }
template <class T> vector<T> read(int n) { vector<T> v; v.reserve(n); REP(i, n) { v.push_back(read<T>()); } return v; }
template <class T> vevector<T> read(int n, int m) { vevector<T> v; REP(i, n) v.push_back(read<T>(m)); return v; }
template <class T> vector<T> readjag() { return read<T>(read<int>()); }
template <class T> vevector<T> readjag(int n) { vevector<T> v; v.reserve(n); REP(i, n) v.push_back(readjag<T>()); return v; }

template <class T> struct iter_pair_t { T beg, end; };
template <class T> iter_pair_t<T> iter_pair(T beg, T end) { return iter_pair_t<T>{beg, end}; }
template <class T> ostream & operator << (ostream &out, const iter_pair_t<T> &v)
{
	std::copy(v.beg, v.end, ostream_iterator<typename decltype(v.beg)::reference>(out, " "));
	return out;
}
template <class T1> ostream & operator << (ostream &out, const vector<T1> &v) { return out << iter_pair(begin(v), end(v)); }
template <class T1> ostream & operator << (ostream &out, const set<T1> &v) { return out << iter_pair(begin(v), end(v)); }
template <class T1, class T2> ostream & operator << (ostream &out, const map<T1, T2> &v) { return out << iter_pair(begin(v), end(v)); }

struct _Reader { istream &cin; template <class T> _Reader operator ,(T &rhs) { cin >> rhs; return *this; } };
struct _Writer { ostream &cout; bool f{ false }; template <class T> _Writer operator ,(const T &rhs) { cout << (f ? " " : "") << rhs; f = true; return *this; } };
#define READ(t,...) t __VA_ARGS__; (_Reader{cin}), __VA_ARGS__
#define WRITE(...) (_Writer{cout}), __VA_ARGS__; cout << '\n'
#define DEBUG(...) (_Writer{cerr}), __VA_ARGS__; cerr << '\n'

void solve();
int main()
{
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);

	//auto temp = ctype<char>::classic_table();
	//vector<ctype<char>::mask> bar(temp, temp + ctype<char>::table_size);
	//bar[':'] |= ctype_base::space;
	//cin.imbue(locale(cin.getloc(), new ctype<char>(bar.data())));

	cin.tie(0);
	ios_base::sync_with_stdio(false);
	cout << fixed;
	cout << setprecision(std::numeric_limits<double>::max_digits10);
	solve();

	return 0;
}

template<class T, class TUpdater>
struct RangeSegTreeT
{
	int size;
	vector<T> tree;
	vector<pair<bool, T>> lazy;
	TUpdater updator;
	T initialValue;

	static constexpr unsigned int msb(unsigned int v) { REP(i, 5) v |= v >> (1 << i); return (v >> 1) + 1; }
	
	RangeSegTreeT(int count, TUpdater updator, T initialValue)
		: size(msb(count - 1) << 1)
		, tree(size * 2)
		, lazy(size * 2)
		, updator(updator)
		, initialValue(initialValue)
	{
		lazy[1] = { true, initialValue };
	}

	void propagate(int l, int r, int i)
	{
		if (lazy[i].first)
		{
			tree[i] = invoke_update(tree[i], lazy[i].second, r - l);
			if (r - l > 1)
			{
				lazy[i * 2] = { true, invoke_update(lazy[i * 2].second, lazy[i].second) };
				lazy[i * 2 + 1] = { true, invoke_update(lazy[i * 2 + 1].second, lazy[i].second) };
			}
			lazy[i] = { false, 0 };
		}
	}

	void update_range(int begin, int end, T value) { update_range(begin, end, 1, 0, size, value); }
	T query(int begin, int end) { return query(begin, end, initialValue); }
	T query(int begin, int end, T initialValue) { return query(begin, end, 1, 0, size, initialValue); }

private:

	T invoke_update(T a, T b, T c = 1) { return updator(a, b, c); }


	void update_range(int s, int e, int i, int l, int r, T value)
	{
		propagate(l, r, i);

		if (r <= s || e <= l) { return; }
		if (s <= l && r <= e) { lazy[i] = { true, invoke_update(lazy[i].second, value) }; return; }
	
		int m = (l + r) / 2;
		if (s < m) { update_range(s, e, i * 2, l, m, value); }
		if (e > m) { update_range(s, e, i * 2 + 1, m, r, value); }
	}

	T query(int s, int e, int i, int l, int r, T value)
	{
		propagate(l, r, i);
		if (r <= s || e <= l) { return value; }
		if (s <= l && r <= e) { return tree[i]; }

		int m = (l + r) / 2;
		if (s < m) { value = invoke_update(value, query(s, e, i * 2, l, m, value)); }
		if (e > m) { value = invoke_update(value, query(s, e, i * 2 + 1, m, r, value)); }
		return value;
	}
};

template <class T, class TUpdator>
RangeSegTreeT<T, TUpdator> RangeSegTree(int n, TUpdator updator, int initialValue)
{
	return RangeSegTreeT<T, TUpdator>(n, updator, initialValue);
}

////////////////////
/// template end ///
////////////////////

void solve()
{
	READ(int, n, q);
	auto tree = RangeSegTree<int>(n, CONV3(a, b, c, b), (1LL << 31) - 1);

	REP(qq, q)
	{
		READ(int, c);
		if (c == 0)
		{
			READ(int, s, t, x);
			tree.update_range(s, t + 1, x);
		}
		else
		{
			READ(int, i);
			int v = tree.query(i, i + 1, 0);
			WRITE(v);
		}
	}

}