#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cctype>
#include <cassert>
#include <climits>
#include <string>
#include <bitset>
#include <cfloat>
#include <random>
#include <iomanip>
#include <unordered_set>
using namespace std;
typedef long double ld;
typedef long long int ll;
typedef unsigned long long int ull;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;
typedef vector<pair<int,int> > vpii;
typedef vector<pair<ll,ll> > vpll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vc> vvc;
typedef vector<vs> vvs;
typedef vector<vll> vvll;
typedef map<int,int> mii;
typedef set<int> si;
#define rep(i,n) for(ll i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define arep(i,v) for(auto i : v)
#define irep(it, stl) for(auto it = stl.begin(); it != stl.end(); it++)
#define drep(i,n) for(int i = (n) - 1; i >= 0; --i)
#define fin(ans) cout << (ans) << '\n'
#define STLL(s) strtoll(s.c_str(), NULL, 10)
#define mp(p,q) make_pair(p, q)
#define pb(n) push_back(n)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define Sort(a) sort(a.begin(), a.end())
#define Rort(a) sort(a.rbegin(), a.rend())
#define MATHPI acos(-1)
#define fi first
#define se second
constexpr int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
constexpr int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> inline bool chmax(T& a,T b){if(a<b){a=b;return 1;} return 0;}
template <class T> inline bool chmin(T& a,T b){if(a>b){a=b;return 1;} return 0;}
template <class T> inline void dump(T &v){irep(i, v){cout<<*i<<((i==--v.end())?'\n':' ');}}
inline string getline(){string s; getline(cin,s); return s;}
inline void yn(const bool b){b?fin("yes"):fin("no");}
inline void Yn(const bool b){b?fin("Yes"):fin("No");}
inline void YN(const bool b){b?fin("YES"):fin("NO");}
struct io{io(){ios::sync_with_stdio(false);cin.tie(0);}};
const int INF = INT_MAX;
constexpr ll LLINF = 1LL<<60;
constexpr ll MOD = 1000000007;
constexpr ld EPS = 1e-11;

template <typename T>
class Sum {
public:
    // 単位元
    T unit;
    
    Sum(void) {
        // 単位元
        unit = 0;
    }

    // 演算関数
    T calc(T a, T b) {
        return a + b; 
    }
};

template <typename T>
struct Min {
public:
    // 単位元
    T unit;
    
    Min(void) {
        // 単位元
        unit = INF;
    }

    // 演算関数
    T calc(T a, T b) {
        return min(a, b); 
    }
};

template <typename T, class MONOID>
class SegmentTree {
public:
    // セグメント木の葉の要素数
    int n;

    // セグメント木
    vector<T> tree;
    vector<T> time;

    // モノイド
    MONOID mono;

    SegmentTree(vector<T> &v) : n(1 << (int)ceil(log2(v.size()))), tree(vector<T>(n << 1,-1)), time(vector<T>(n << 1,-1)) {
    }

    // k番目の値(0-indexed)をxに変更
    int get(int k) {
        k += n;
        int res = tree[k];
        int maxTime=time[k];
        for(k = k >> 1; k > 0; k >>= 1){
            if(time[k]>maxTime){
                res=tree[k];
                maxTime=time[k];
            }
        }
        return res;
    }

    // [l, r)の最小値(0-indexed)を求める．
    void update(int l, int r, T x, int t) {
        l += n;
        r += n;
        while(l < r) {
            if(l & 1) {
                tree[l]=x;
                time[l]=t;
                l++;
            }
            if(r & 1) {
                tree[r-1]=x;
                time[r-1]=t;
                r--;
            }
            l >>= 1;
            r >>= 1;
        }
    }

    T operator[](int k) {
        // st[i]で添字iの要素の値を返す
        if(k - n >= 0 || k < 0) {
            return -INF;
        }
        return tree[tree.size() - n + k];
    }

    void show(void) {
        int ret = 2;
        for(int i = 1; i < 2*n; ++i) {
            if(tree[i] == mono.unit) cout << "UNIT ";
            else cout << tree[i] << " ";
            if(i == ret - 1) {
                cout << endl;
                ret <<= 1;
            }
        }
        cout << endl;
    }
};

int main() {
    
    int n,q;
    cin>>n>>q;
    vi v(n,-1);
    SegmentTree<int,Sum<int>> st(v);
    rep(i,q){
        int com;
        cin>>com;
        if(com==0){
            int s,t,x;
            cin>>s>>t>>x;
            st.update(s,t+1,x, i);
        }
        else {
            int idx;
            cin>>idx;
            int ans=st.get(idx);
            
            if(ans!=-1)fin(ans);
            else fin(2147483647);
        }
        // st.show();
    }
    
}


Measured memory_bytes: 5400