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)

#include <bits/stdc++.h>
#include <cmath>

using namespace std;
typedef long long ll;
//typedef unsigned long long ll;

#define rep(i, n) for (int i = 0; i < (n); ++i)
//#define rep(i, n) for (ll i = 0; i < (n); ++i)
//#define sz(x) ll(x.size())
//typedef pair<ll, int> P;
typedef pair<ll, ll> P;
//const double INF = 1e10;
const ll INF = LONG_LONG_MAX / 10;
//const ll INF = (1ll << 31) - 1;
//const ll INF = 1e15;
const ll MINF = LONG_LONG_MIN;
//const int INF = INT_MAX / 10;
#define cmin(x, y) x = min(x, y)
#define cmax(x, y) x = max(x, y)
//typedef pair<int, int> P;
//typedef pair<double, double> P;

bool contain(set<P> &s, P a) { return s.find(a) != s.end(); }

//ifstream myfile("C:\\Users\\riku\\Downloads\\0_00.txt");
//ofstream outfile("log.txt");
//outfile << setw(6) << setfill('0') << prefecture << setw(6) << setfill('0') << rank << endl;
// std::cout << std::bitset<8>(9);


void print_line(vector<ll> &line) {
    if (line.size() == 0ll) {
        cout << endl;
        return;
    }
    for (ll i = 0; i < line.size(); i++) {
        cout << line[i];
        if (i == line.size() - 1) cout << endl;
        else cout << ' ';
    }
}


typedef priority_queue<long long, vector<long long>, greater<long long>> PQ_ASK;
const int mod = 1000000007;

// https://onlinejudge.u-aizu.ac.jp/solutions/problem/DSL_2_D/review/3635072/beet/C++14
template<typename E>
struct SegmentTree {
    using H = function<E(E, E)>;
    int n, height;
    H h;
    E ei;
    vector<E> laz;

    SegmentTree(H h, E ei) : h(h), ei(ei) {}

    void init(int n_) {
        n = 1;
        height = 0;
        while (n < n_) n <<= 1, height++;
        laz.assign(2 * n, ei);
    }

    inline void eval(int k) {
        if (laz[k] == ei) return;
        laz[(k << 1) | 0] = h(laz[(k << 1) | 0], laz[k]);
        laz[(k << 1) | 1] = h(laz[(k << 1) | 1], laz[k]);
        laz[k] = ei;
    }

    inline void thrust(int k) {
        for (int i = height; i; i--) eval(k >> i);
    }

    void update(int a, int b, E x) {
        thrust(a += n);
        thrust(b += n - 1);
        for (int l = a, r = b + 1; l < r; l >>= 1, r >>= 1) {
            if (l & 1) laz[l] = h(laz[l], x), l++;
            if (r & 1) --r, laz[r] = h(laz[r], x);
        }
    }

    E get_val(int a) {
        thrust(a += n);
        return laz[a];
    }

    void set_val(int a, E x) {
        thrust(a += n);
        laz[a] = x;
    }
};


int main() {

    int n, q;
    cin >> n >> q;
    auto h = [](int a, int b) {
        (void) a;
        return b;
    };
    SegmentTree<int> st(h, INT_MAX);
    st.init(n);

    rep(i, q) {
        int query;
        cin >> query;

        if (query == 0) {
            int s, t, x;
            cin >> s >> t >> x;
            st.update(s, t + 1, x);
        } else if (query == 1) {
            int x;
            cin >> x;
            cout << st.get_val(x) << endl;
        }

    }

}