#include <bits/stdc++.h>
#define int long long int
#define MOD(x) ((x % MOD_N) + MOD_N) % MOD_N
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define FORE(i,a,b) for(int i=(a);i<=(b);++i)
#define RFOR(i,a,b) for(int i=(b)-1;i>=(a);--i)
#define RFORE(i,a,b) for(int i=(b);i>=(a);--i)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(c) (c).begin(),(c).end()
#define RALL(c) (c).rbegin(),(c).rend()
#define SORT(c) sort(ALL(c))
#define RSORT(c) sort(RALL(c))
#define SZ(c) (int)((c).size())
#define EACH(i,v) for(auto i=v.begin();i!=v.end();++i)
#define REACH(i,v) for(auto i=v.rbegin();i!=v.rend();++i)
#define LB(c,x) distance((c).begin(),lower_bound(ALL(c),x))
#define UB(c,x) distance((c).begin(),upper_bound(ALL(c),x))
#define COUNT(c,x) (lower_bound(ALL(c),x)-upper_bound(ALL(c),x))
#define UNIQUE(c) SORT(c); (c).erase(unique(ALL(c)),(c).end());
#define COPY(c1,c2) copy(ALL(c1),(c2).begin())
#define EXIST(s,e) (bool)((s).find(e)!=(s).end())
#define PB push_back
#define MP make_pair
#define DUMP(x)  cerr<<#x<<" = "<<(x)<<endl;
#define NL cerr<<endl;
using namespace std;
template<typename T,typename U> using P=pair<T,U>;
template<typename T> using V=vector<T>;
template<typename T>bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<typename T>bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<typename T>T sum(vector<T>&v){return accumulate(ALL(v),T());}
template<typename T>T sum(vector<T>&v,int a,int b){return accumulate(v.begin()+a,v.begin()+b,T());}
template<typename T>T max(vector<T>&v){return *max_element(ALL(v));}
template<typename T>T min(vector<T>&v){return *max_element(ALL(v));}
template<typename T>T max_index(vector<T>&v){return distance((v).begin(),max_element(ALL(v)));}
template<typename T>T min_index(vector<T>&v){return distance((v).begin(),min_element(ALL(v)));}

struct edge { int to, cost; };

template<typename T>auto&operator<<(ostream&s,const vector<T>&v){s<<"[";bool a=1;for(auto e:v){s<<(a?"":" ")<<e;a=0;}s<<"]";return s;}
template<typename T,typename U>auto&operator<<(ostream&s,const pair<T,U>&p){s<<"("<<p.first<<","<<p.second<<")";return s;}
template<typename T>auto&operator<<(ostream&s,const set<T>&st){s<<"{";bool a=1;for(auto e:st){s<<(a?"":" ")<<e;a=0;}s<<"}";return s;}
template<typename T,typename U>auto&operator<<(ostream&s,const map<T,U>&m){s<<"{";bool a=1;for(auto e:m){s<<(a?"":" ")<<e.first<<":"<<e.second;a=0;}s<<"}";return s;}

const int INF = 1e18;
const int MOD_N = 1e9+7;

template<typename T, typename F> class SegmentTree
{
   private:
      int n;
      vector<T> node;
      F f;
   public:
      SegmentTree(int sz, const F& func, T inf) : f(func) {
         n = 1; while(n < sz) n *= 2;
         node.resize(2*n-1, inf);
      }
      SegmentTree(const vector<T>& v, const F& func, T inf) : f(func) {
         int sz = v.size();
         n = 1; while(n < sz) n *= 2;
         node.resize(2*n-1, inf);
         for(int i=0; i<sz; i++) node[i+n-1] = v[i];
      }
      void update(int a, int b, T val, int k=0, int l=0, int r=-1) {
         // update [a,b)
         if(r < 0) r = n;
         if(r <= a || b <= l) return;
         if(a <= l && r <= b) { node[k] = val; return; }
         update(a, b, val, 2*k+1, l, (l+r)/2);
         update(a, b, val, 2*k+2, (l+r)/2, r);
      }
      T find(int i) {
         i += (n - 1);
         T res = node[i];
         while (i > 0) {
            i = (i - 1) / 2;
            res = f(res, node[i]);
         }
         return res;
      }
};
template<typename T> class RUQ
{
   private:
      int t = 0;
      SegmentTree<P<T,T>,function<P<T,T>(P<T,T>,P<T,T>)>> st;
   public:
      RUQ(int sz, T init) : st(sz, [](P<T,T> a,P<T,T> b){return max(a,b);}, MP(-INF,init)) {}
      RUQ(const vector<T>& v, T init) : st(v.size(), [](P<T,T> a,P<T,T> b){return max(a,b);}, MP(-INF,init)) {
         for (int i = 0; i < v.size(); i++) {
            st.update(i,i+1,make_pair(-1,v[i]));
         }
      }
      void update(int a, int b, T val) {
         // update [a,b)
         st.update(a,b,MP(t++,val));
      }
      T find (int i) {
         return st.find(i).second;
      }
};

signed main()
{
   int n, q; cin >> n >> q;
   V<int> c(q), s(q), t(q), x(q), id(q);
   REP(i, q) {
      cin >> c[i];
      if (c[i] == 0) {
         cin >> s[i] >> t[i] >> x[i];
      } else {
         cin >> id[i];
      }
   }

   RUQ<int> ruq(n, (1LL<<31)-1);
   REP(i, q) {
      if (c[i] == 0) {
         ruq.update(s[i], t[i]+1, x[i]);
      } else {
         cout << ruq.find(id[i]) << endl;
      }
   }
   return 0;
}



Measured memory_bytes: 10724