#include <bits/stdc++.h>
#ifdef LOCAL_DEBUG
#define DEBUG 1
#define CERR if(DEBUG) cerr
#define MACRO(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,NAME,...) NAME
#define pr(...) CERR<<MACRO(__VA_ARGS__,pr10,pr9,pr8,pr7,pr6,pr5,pr4,pr3,pr2,pr1)(__VA_ARGS__)<<endl
#define pr1(a) (#a)<<"="<<(a)<<" "
#define pr2(a,b) pr1(a)<<pr1(b)
#define pr3(a,b,c) pr1(a)<<pr2(b,c)
#define pr4(a,b,c,d) pr1(a)<<pr3(b,c,d)
#define pr5(a,b,c,d,e) pr1(a)<<pr4(b,c,d,e)
#define pr6(a,b,c,d,e,f) pr1(a)<<pr5(b,c,d,e,f)
#define pr7(a,b,c,d,e,f,g) pr1(a)<<pr6(b,c,d,e,f,g)
#define pr8(a,b,c,d,e,f,g,h) pr1(a)<<pr7(b,c,d,e,f,g,h)
#define pr9(a,b,c,d,e,f,g,h,i) pr1(a)<<pr8(b,c,d,e,f,g,h,i)
#define pr10(a,b,c,d,e,f,g,h,i,j) pr1(a)<<pr9(b,c,d,e,f,g,h,i,j)
#define prArr(a){CERR<<(#a)<<"={";int i=0;for(auto t:(a))CERR<<(i++?", ":"")<<t;CERR<<"}"<<endl;}
#else
#define DEBUG 0
#define pr(...)
#define prArr(a)
#endif
using namespace std;
using Int = long long;
using _int = int;
using ll = long long;
using Double = long double;
const Int INF = (1LL<<60)+1e9; // ~ 1.15 * 1e18
const Int mod = (1e9)+7;
const Double EPS = 1e-8;
const Double PI = 6.0 * asin((Double)0.5);
using P = pair<Int,Int>;
template<class T> T Max(T &a,T b){return a=max(a,b);}
template<class T> T Min(T &a,T b){return a=min(a,b);}
template<class T1, class T2> ostream& operator<<(ostream& o,pair<T1,T2> p){return o<<"("<<p.first<<","<<p.second<<")";}
template<class T1, class T2, class T3> ostream& operator<<(ostream& o,tuple<T1,T2,T3> t){return o<<"("<<get<0>(t)<<","<<get<1>(t)<<","<<get<2>(t)<<")";}
template<class T1, class T2> istream& operator>>(istream& i,pair<T1,T2> &p){return i>>p.first>>p.second;}
template<class T> ostream& operator<<(ostream& o,vector<T> a){Int i=0;for(T t:a)o<<(i++?" ":"")<<t;return o;}
template<class T> istream& operator>>(istream& i,vector<T> &a){for(T &t:a)i>>t;return i;}
//INSERT ABOVE HERE

template<typename D, int useAssert = 1>
class RMQ{
public :
  struct T{ //遅延データ
    int type; //0 - empty, 1 - update, 2 - ifUpdate
    D value;
    T(int type, D value):type(type), value(value){}
  };

  int n, n_;
  D initValue;        //範囲外の時に返す値
  vector<D> dat;
  vector<T> td;
  int toMax;          //0 -> RangeMin 1->RangeMax;

  RMQ(){n=-1;}
  RMQ(int n_, D initValue, int toMax = 0):n_(n_), initValue(initValue), toMax(toMax){
    n=1;
    while(n<n_)n*=2;
    td.resize(2*n-1, T(0, initValue));
    dat.resize(2*n-1, initValue);
  }

  //目的データのマージ
  inline D mergeD(D l, D r){return toMax? max(l, r):min(l, r);}

  //遅延データのマージ
  inline T mergeT(const T &from,const T &to){
    if(to.type == 0) return from;
    if(from.type == 0) return to; //from-empty
    if(to.type == 1) return to; //to-update;
    if(to.type == 2) return T(from.type, mergeD(from.value, to.value)); //to-ifupdate
    if(useAssert) assert(0);
  }

  //目的データに遅延データを反映
  inline void apply(D &a, const T &b){
    if(b.type == 0) return;
    if(b.type == 1) a = b.value; //update
    else a = mergeD(a, b.value); // if-update
  }

  D dfs(int a, int b,const T x, int k, int l, int r){
    if(r <= a || b <= l) return x.type == 0? initValue : dat[k];
    if(a <= l && r <= b){
      td[k] = mergeT(td[k], x);
      apply(dat[k], x);
      return dat[k];
    }
    int kl = k * 2 + 1, kr = k * 2 + 2;
    { //遅延を子に反映
      td[kl] = mergeT(td[kl], td[k]);
      td[kr] = mergeT(td[kr], td[k]);
      apply(dat[kl], td[k]);
      apply(dat[kr], td[k]);
      td[k] = T(0, initValue);
    }
    D vl = dfs(a, b, x, kl, l, (l+r)/2);
    D vr = dfs(a, b, x, kr, (l+r)/2, r);
    return x.type == 0? mergeD(vl,vr) : (dat[k] = mergeD(vl, vr));
  }

  //[l,r)の値をxに変更　update(l,r,x)
  void update(int l,int r, D x){
    if(useAssert) assert(l <= r), assert(l <= n && r <= n), assert(l >= 0 && r >= 0);
    dfs(l, r,  T(1, x), 0, 0, n);
  }

  //[l,r)の値をもしもxの方が小さければ変更　ifupdate(l,r,x)
  //toMaxのときは[l,r)の値をもしもxの方が大きければ変更　ifupdate(l,r,x)
  void ifupdate(int l,int r, D x){
    if(useAssert) assert(l <= r), assert(l <= n && r <= n), assert(l >= 0 && r >= 0);
    dfs(l, r,  T(2, x), 0, 0, n);
  }

  //[l,r)の最小値を得る　get(l,r);
  D get(int l,int r){
    if(useAssert) assert(l <= r), assert(l <= n && r <= n), assert(l >= 0 && r >= 0);
    return dfs(l, r, T(0, initValue), 0 , 0 ,n);
  }
};

signed main(){
  srand((unsigned)time(NULL));
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(12);

  int n, q;
  cin>>n>>q;

  RMQ<int, 0> seg(n, (1LL<<31)-1, 0);
  while(q--){
    int cmd, s, t;
    cin>>cmd>>s>>t;
    if(cmd == 0){
      int x;
      cin>>x;
      seg.update(s, t+1, x);
    }
    else cout<<seg.get(s, t+1)<<endl;
  }

  return 0;
}



Measured memory_bytes: 6008