#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> P;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
// #define int long long
#define pb push_back
#define mp make_pair
#define eps 1e-9
#define INF 2000000000 //2e9
#define LLINF 1000000000000000000ll // 1e18
#define fi first
#define sec second
#define all(x) (x).begin(),(x).end()
#define sq(x) ((x)*(x))
#define dmp(x) cerr << #x << ": " << x << endl;

template<class T> void chmin(T& a,const T& b){if(a>b)a=b;}
template<class T> void chmax(T& a,const T& b){if(a<b)a=b;}

template<class T> using MaxHeap = priority_queue<T>;
template<class T> using MinHeap = priority_queue<T,vector<T>,greater<T>>;
template<class T> vector<T> vect(int len,T elem){ return vector<T>(len,elem); }

template<class T,class U>
ostream& operator << (ostream& os,const pair<T,U>& p){
  os << p.fi << ',' << p.sec; return os;
}
template<class T,class U>
istream& operator >> (istream& is,pair<T,U>& p){
  is >> p.fi >> p.sec; return is;
}
template<class T>
ostream& operator << (ostream &os,const vector<T> &vec){
  for(int i=0;i<vec.size();i++){
    os << vec[i];
    if(i+1<vec.size())os << ' ';
  }
  return os;
}
template<class T>
istream& operator >> (istream &is,vector<T>& vec){
  for(int i=0;i<vec.size();i++)is >> vec[i];
  return is;
}
void fastio(){
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout<<fixed<<setprecision(20);
}

namespace Math{
  template<int MOD> // if inv is needed, this shold be prime.
  struct ModInt{ ll val; ModInt():val(0ll){}
    ModInt(const ll& v):val(((v%MOD)+MOD)%MOD){}
    bool operator==(const ModInt& x)const{return val==x.val;}
    bool operator!=(const ModInt& x)const{return !(*this==x);}
    bool operator<(const ModInt& x)const{return val<x.val;}
    bool operator>(const ModInt& x)const{return val>x.val;}
    bool operator>=(const ModInt& x)const{return !(*this<x);}
    bool operator<=(const ModInt& x)const{return !(*this>x);}
    ModInt operator-()const{return ModInt(MOD-val);}
    ModInt inv()const{return this->pow(MOD-2);}
    ModInt& operator+=(const ModInt& x){if((val+=x.val)>=MOD)val-=MOD;return *this;}
    ModInt& operator-=(const ModInt& x){if((val+=MOD-x.val)>=MOD)val-=MOD;return *this;}
    ModInt& operator*=(const ModInt& x){(val*=x.val)%=MOD;return *this;}
    ModInt& operator/=(const ModInt& x){return *this *= x.inv();};
    ModInt operator+(const ModInt& x)const{return ModInt(*this)+=x;}
    ModInt operator-(const ModInt& x)const{return ModInt(*this)-=x;}
    ModInt operator*(const ModInt& x)const{return ModInt(*this)*=x;}
    ModInt operator/(const ModInt& x)const{return ModInt(*this)/=x;}
    friend istream& operator>>(istream&i,ModInt& x){ll v;i>>v;x=v;return i;}
    friend ostream& operator<<(ostream&o,const ModInt& x){o<<x.val;return o;}
    ModInt pow(ll x)const{
      auto res = ModInt(1ll);
      auto b = *this;
      while(x){
        if(x&1)res *= b;
        x >>= 1;
        b *= b;
      }
      return res;
    }
  };

  template<int MOD>
  ModInt<MOD> pow(ModInt<MOD> a,ll x){
    ModInt<MOD> res = ModInt<MOD>(1ll);
    while(x){
      if(x&1)res *= a;
      x >>= 1;
      a *= a;
    }
    return res;
  }

  constexpr int MOD = 1e9+7;
  // constexpr int MOD = 998244353;
  using mint = ModInt<MOD>;

  vector<mint> inv,fac,facinv;
  // notice: 0C0 = 1 
  ModInt<MOD> nCr(int n,int r){
    assert(!(n<r));
    assert(!(n<0||r<0));
    return fac[n]*facinv[r]*facinv[n-r];
  }
  void init(int SIZE){
    fac.resize(SIZE+1);
    inv.resize(SIZE+1);
    facinv.resize(SIZE+1);
    fac[0] = inv[1] = facinv[0] = mint(1ll);
    for(int i=1;i<=SIZE;i++)fac[i]=fac[i-1]*mint(i);
    for(int i=2;i<=SIZE;i++)inv[i]=mint(0ll)-mint(MOD/i)*inv[MOD%i];
    for(int i=1;i<=SIZE;i++)facinv[i]=facinv[i-1]*inv[i];
    return;
  }
  template<class T>
  int digit(T x){
    int res = 0;
    while(x){ x /= T(10); res++; }
    return res;
  }
  template<class T>
  int digit_sum(T x){
    int res = 0;
    while(x){ res+=x%10; x/=10; }
    return res;
  }
  template<class T>
  T gcd(T x,T y){
    if(y==T(0))return x;
    else return gcd(y,x%y);
  }
}

namespace DS{
  template<class T>
  struct RangeSum{
    vector<T> vec;
    RangeSum(){}
    RangeSum(vector<T> elems):vec(elems){
      for(int i=1;i<vec.size();i++){
        vec[i] += vec[i-1];
      }
    }
    T sum(int l,int r){
      if(l>r)return T(0);
      if(l==0)return vec[r];
      else return vec[r]-vec[l-1];
    }
  };
  template<class T>
  struct BIT{
    int N;
    vector<T> bit;
    BIT(int N):N(N){
      bit = vector<T>(N+1,T(0));
    }
    void add(int i,T x){
      i++;
      while(i<=N){ bit[i]+=x; i+=i&-i; }
      return;
    }
    T sum(int i){
      i++;
      T res = T(0);
      while(i>0){ res+=bit[i]; i-=i&-i; }
      return res;
    }
    T sum(int l,int r){// [l,r]
      assert(l<=r);
      if(l==0)return sum(r);
      else return sum(r)-sum(l-1);
    }
  };
  template<class T>
  struct SlideMin{
    vector<T> v;
    deque<int> deq;
    SlideMin(vector<T> &v):v(v){}
    void add(int id){ // add v[id]
      while(!deq.empty()&&v[deq.back()]>=v[id])deq.pop_back();
      deq.push_back(id);
    }
    T get(int id){ // [id,added]
      while(!deq.empty()&&deq.front()<id)deq.pop_front();
      assert(!deq.empty());
      return v[deq.front()];
    }
  };
  template<class T>
  struct SlideMax{
    vector<T> v;
    deque<int> deq;
    SlideMax(vector<T> &v):v(v){}
    void add(int id){
      while(!deq.empty()&&v[deq.back()]<=v[id])deq.pop_back();
      deq.push_back(id);
    }
    T get(int id){ // [id,added]
      while(!deq.empty()&&deq.front()<id)deq.pop_front();
      assert(!deq.empty());
      return v[deq.front()];
    }
  };
  template<class D,class O>
  struct LazySegmentTree{
    using DMerger = function<D(D,D)>;
    using OMerger = function<O(O,O)>;
    using Applier = function<D(D,O,int)>;

    int length;

    D d_unit;
    O o_unit;

    vector<D> seg;
    vector<O> lazy;

    DMerger dm;
    OMerger om;
    Applier app;

    void lazy_evaluate(int k,int len){
      if(lazy[k] == o_unit) return;
      if(len>1){
        lazy[2*k+1] = om(lazy[2*k+1],lazy[k]);
        lazy[2*k+2] = om(lazy[2*k+2],lazy[k]);
      }
      seg[k] = app(seg[k],lazy[k],len);
      lazy[k] = o_unit;
    }
    void update(int a,int b,int k,int l,int r,O x){
      lazy_evaluate(k,r-l);
      if(r<=a||b<=l)return;
      else if(a<=l&&r<=b){
        lazy[k] = om(lazy[k],x);
        lazy_evaluate(k,r-l);
      }else{
        update(a,b,k*2+1,l,(l+r)/2,x);
        update(a,b,k*2+2,(l+r)/2,r,x);
        seg[k] = dm(seg[k*2+1],seg[k*2+2]);
      }
    }
    void update(int a,int b,O x){
      update(a,b,0,0,length,x);
    }
    D query(int a,int b,int k,int l,int r){
      lazy_evaluate(k,r-l);
      if(r<=a||b<=l)return d_unit; 
      else if(a<=l&&r<=b)return seg[k];
      else{
        D lch = query(a,b,k*2+1,l,(l+r)/2);
        D rch = query(a,b,k*2+2,(l+r)/2,r);
        return dm(lch,rch);
      }
    }
    D query(int a,int b){
      return query(a,b,0,0,length);
    }
    LazySegmentTree(int n,D d_unit,O o_unit,DMerger dm,OMerger om,Applier app)
      :length(1),d_unit(d_unit),o_unit(o_unit),dm(dm),om(om),app(app) {
      while(length<n){ length <<= 1; }
      seg.assign(length * 2, d_unit);
      lazy.assign(length * 2, o_unit);
    }
    LazySegmentTree(vector<D> vec,D d_unit,O o_unit,DMerger dm,OMerger om,Applier app)
      :length(1),d_unit(d_unit),o_unit(o_unit),dm(dm),om(om),app(app) {
      while(length<vec.size()){ length <<= 1; }
      seg.assign(length * 2, d_unit);
      lazy.assign(length * 2, o_unit);
      for(int i=0;i<vec.size();i++)seg[length-1+i] = vec[i];
      for(int i=length-2;i>=0;i--)seg[i] = dm(seg[i*2+1],seg[i*2+2]);
    }
  };
  // RangeAddRangeSum update : a[l,r) += c
  // verified https://atcoder.jp/contests/abc153/submissions/9866001
  template<class T>
  LazySegmentTree<T,T> RangeAddRangeSum(int size){
    auto dm = [](T a,T b){return a+b;};
    auto om = [](T a,T b){return a+b;};
    auto app = [](T dat,T lz,int len){return dat+lz*T(len);};
    return LazySegmentTree<T,T>(size,T(0),T(0),dm,om,app);
  }
  template<class T>
  LazySegmentTree<T,T> RangeAddRangeSum(vector<T> vec){
    auto dm = [](T a,T b){return a+b;};
    auto om = [](T a,T b){return a+b;};
    auto app = [](T dat,T lz,int len){return dat+lz*T(len);};
    return LazySegmentTree<T,T>(vec,T(0),T(0),dm,om,app);
  }
  // RangeAddRangeMin
  // NOT verified yet
  LazySegmentTree<ll,ll> RangeAddRangeMin(int size){
    auto dm = [](ll a,ll b){return min(a,b);};
    auto om = [](ll a,ll b){return a+b;};
    auto app = [](ll dat,ll lz,int len){return dat+lz;};
    return LazySegmentTree<ll,ll>(size,LLINF,0ll,dm,om,app);
  }
  LazySegmentTree<ll,ll> RangeAddRangeMin(vector<ll> vec){
    auto dm = [](ll a,ll b){return min(a,b);};
    auto om = [](ll a,ll b){return a+b;};
    auto app = [](ll dat,ll lz,int len){return dat+lz;};
    return LazySegmentTree<ll,ll>(vec,LLINF,0ll,dm,om,app);
  }
  // RangeAffineRangeSum update (l,r,(p,q)) : a[i] = p * a[i] + q { i in [l,r) }
  // verified https://judge.yosupo.jp/submission/3354
  template<class T>
  LazySegmentTree<ll,pair<T,T>> RangeAffineRangeSum(int size){
    using f = pair<T,T>;
    auto dm = [](T a,T b){return a+b;};
    auto om = [](f a,f b){return f(b.fi*a.fi,b.fi*a.sec+b.sec);};
    auto app = [](T dat,f lz,int len){return lz.fi*dat+lz.sec*T(len);};
    return LazySegmentTree<T,f>(size,T(0),f(T(1),T(0)),dm,om,app);
  }
  template<class T>
  LazySegmentTree<T,pair<T,T>> RangeAffineRangeSum(vector<T> vec){
    using f = pair<T,T>;
    auto dm = [](T a,T b){return a+b;};
    auto om = [](f a,f b){return f(b.fi*a.fi,b.fi*a.sec+b.sec);};
    auto app = [](T dat,f lz,int len){return lz.fi*dat+lz.sec*T(len);};
    return LazySegmentTree<T,f>(vec,T(0),f(T(1),T(0)),dm,om,app);
  }
}

namespace Util{
  template<class T>
  vector<pair<T,int>> runLength(vector<T> v){
    vector<pair<T,int>> res;
    for(int i=0;i<v.size();i++){
      if(res.empty()||res.back().first!=v[i])res.push_back(make_pair(v[i],1));
      else res.back().second++;
    }
    return res;
  }
  template<class T>
  void compress(vector<T> &v){
    sort(v.begin(),v.end());
    v.erase(unique(v.begin(),v.end()),v.end());
  }
}

template<class D>
struct SegmentTree{
  using DMerger = function<D(D,D)>;
  int length;
  D d_unit;
  vector<D> seg;
  DMerger dm;
  void update(int k,D x){
    k += length-1;
    seg[k] = x;
    while(k){
      k = (k-1)/2;
      seg[k] = dm(seg[2*k+1],seg[2*k+2]);
    }
  }
  D query(int a,int b,int k,int l,int r){
    if(r<=a||b<=l)return d_unit; 
    else if(a<=l&&r<=b)return seg[k];
    else{
      D lch = query(a,b,k*2+1,l,(l+r)/2);
      D rch = query(a,b,k*2+2,(l+r)/2,r);
      return dm(lch,rch);
    }
  }
  D query(int a,int b){
    return query(a,b,0,0,length);
  }
  D operator [] (int id) const {
    assert(0<=id&&id<length);
    return seg[length-1+id];
  }
  SegmentTree(int n,D d_unit,DMerger dm)
    :length(1),d_unit(d_unit),dm(dm) {
    while(length<n){ length <<= 1; }
    seg.assign(length * 2, d_unit);
  }
  SegmentTree(vector<D> vec,D d_unit,DMerger dm)
    :length(1),d_unit(d_unit),dm(dm) {
    while(length<vec.size()){ length <<= 1; }
    seg.assign(length * 2, d_unit);
    for(int i=0;i<vec.size();i++)seg[length-1+i] = vec[i];
    for(int i=length-2;i>=0;i--)seg[i] = dm(seg[i*2+1],seg[i*2+2]);
  }
};

template<class D>
struct SegmentTreeBeats{
  using DMerger = function<D(D,D)>;
  vector<D> seg;
  int length;
  DMerger dm;
  D d_unit;
  SegmentTreeBeats(const vector<D>& vec,DMerger dm,D d_unit = D()):length(1),dm(dm){
    while(length<vec.size())length <<= 1;
    seg.assign(length*2,d_unit);
    for(int i=0;i<vec.size();i++){
      seg[i+length-1] = vec[i];
    }
    for(int i=length-2;i>=0;i--){
      seg[i] = dm(seg[i*2+1],seg[i*2+2]);
    }
  }
  template<class F,class... Args>
  void update(int a,int b,int k,int l,int r,F break_or_puttag,Args... args){
    if(r<=a||b<=l)return;
    if(a<=l&&r<=b&&(seg[k].*break_or_puttag)(args...))return;
    seg[k].pushdown(seg[k*2+1],seg[k*2+2]);
    update(a,b,k*2+1,l,(l+r)/2,break_or_puttag,args...);
    update(a,b,k*2+2,(l+r)/2,r,break_or_puttag,args...);
    seg[k] = dm(seg[k*2+1],seg[k*2+2]);
  }
  template<class F,class... Args>
  void update(int a,int b,F break_or_puttag,Args... args){
    update(a,b,0,0,length,break_or_puttag,args...);
  }
  template<class Getter,class QMerger,class Q>
  Q query(int a,int b,int k,int l,int r,Getter getter,QMerger qm,Q q_unit){
    if(r<=a||b<=l)return q_unit;
    if(a<=l&&r<=b)return (seg[k].*getter)();
    seg[k].pushdown(seg[k*2+1],seg[k*2+2]);
    Q lch = query(a,b,k*2+1,l,(l+r)/2,getter,qm,q_unit);
    Q rch = query(a,b,k*2+2,(l+r)/2,r,getter,qm,q_unit);
    return qm(lch,rch);
  }
  template<class Getter,class QMerger,class Q>
  Q query(int a,int b,Getter getter,QMerger qm,Q q_unit){
    return query(a,b,0,0,length,getter,qm,q_unit);
  }
};

// requirements :
// static Data merge(Data l,Data r)
// void pushdown(Data& l,Data& r) (push down tag)
// 
// for each update query :
// bool break_or_puttag_[QUERY] (TAGTYPE tag)
//   if puttag condition is satisfied, update data and put tag
//   return : if break condition or puttag condition is satisfied, return true, otherwise return false

struct Data{
  ll tag,num,sum,mx,mi,second_mx,second_mi,mx_num,mi_num;
  Data(ll v = 0ll):tag(0ll),num(1ll),sum(v),mx(v),mi(v),second_mx(-LLINF),second_mi(LLINF),mx_num(1),mi_num(1){}
  static Data merge(Data l,Data r){
    Data ret;
    ret.tag = 0;
    ret.sum = l.sum+r.sum;
    ret.num = l.num+r.num;
    ret.mx = max(l.mx,r.mx);
    ret.mi = min(l.mi,r.mi);

    ret.second_mx = -LLINF;
    if(l.mx==ret.mx){
      if(r.mx < ret.mx)chmax(ret.second_mx,r.mx);
      chmax(ret.second_mx,l.second_mx);
      chmax(ret.second_mx,r.second_mx);
    }
    if(r.mx==ret.mx){
      if(l.mx < ret.mx)chmax(ret.second_mx,l.mx);
      chmax(ret.second_mx,l.second_mx);
      chmax(ret.second_mx,r.second_mx);
    }

    ret.second_mi = LLINF;
    if(l.mi==ret.mi){
      if(r.mi > ret.mi)chmin(ret.second_mi,r.mi);
      chmin(ret.second_mi,l.second_mi);
      chmin(ret.second_mi,r.second_mi);
    }
    if(r.mi==ret.mi){
      if(l.mi > ret.mi)chmin(ret.second_mi,l.mi);
      chmin(ret.second_mi,l.second_mi);
      chmin(ret.second_mi,r.second_mi);
    }

    ret.mx_num = 0;
    if(ret.mx==l.mx) ret.mx_num += l.mx_num;
    if(ret.mx==r.mx) ret.mx_num += r.mx_num;

    ret.mi_num = 0;
    if(ret.mi==l.mi) ret.mi_num += l.mi_num;
    if(ret.mi==r.mi) ret.mi_num += r.mi_num;

    return ret;
  }
  bool add(ll x){
    sum += num*x;
    mx += x;
    if(second_mx!=-LLINF)second_mx += x;
    mi += x;
    if(second_mi!=LLINF)second_mi += x;
    tag += x;
    return true;
  }
  void pushdown(Data& l,Data& r){
    l.add(tag);
    r.add(tag);
    tag = 0ll;
    if(l.mx > mx)l.chmin_query(mx);
    if(r.mx > mx)r.chmin_query(mx);
    if(l.mi < mi)l.chmax_query(mi);
    if(r.mi < mi)r.chmax_query(mi);
  }
  bool chmax_query(ll x){
    if(mi>=x)return true;
    if(second_mi>x){
      if(second_mi==LLINF){ // 1 value only
        sum += (x-mi)*mi_num;
        mi = x;
        mx = x;
      }
      else if(second_mi==mx){ // 2 value only
        sum += (x-mi)*mi_num;
        mi = x;
        second_mx = x;
      }else{
        sum += (x-mi)*mi_num;
        mi = x;
      }
      return true;
    }
    return false;
  }
  bool chmin_query(ll x){
    if(mx<=x)return true;
    if(second_mx<x){
      if(second_mx==-LLINF){ // 1 value only
        sum -= (mx-x)*mx_num;
        mx = x;
        mi = x;
      }
      else if(second_mi==mx){ // 2 value only
        sum -= (mx-x)*mx_num;
        mx = x;
        second_mi = x;
      }else{
        sum -= (mx-x)*mx_num;
        mx = x;
      }
      return true;
    }
    return false;
  }
  ll get_sum(){
    return sum;
  }
  ll get_min(){
    return mi;
  }
};

void yosupo_RangeChminChmaxAddRangeSum(){
  int n,q;
  cin >> n >> q;
  vector<Data> vec;
  for(int i=0;i<n;i++){
    ll a;
    cin >> a;
    vec.emplace_back(a);
  }
  SegmentTreeBeats<Data> seg(vec,Data::merge);
  for(int i=0;i<q;i++){
    int type,l,r,b; cin >> type;
    if(type==0){
      cin >> l >> r >> b;
      seg.update(l,r,&Data::chmin_query,b);
    }
    if(type==1){
      cin >> l >> r >> b;
      seg.update(l,r,&Data::chmax_query,b);
    }
    if(type==2){
      cin >> l >> r >> b;
      seg.update(l,r,&Data::add,b);
    }
    if(type==3){
      cin >> l >> r;
      cout << seg.query(l,r,&Data::get_sum,[](ll x,ll y){return x+y;},0ll) << endl;
    }
    /*
    for(int j=0;j<seg.seg.size();j++){
      cout << "id : " << j << endl;
      cout << " mx : " << seg.seg[j].mx;
      cout << " second_mx : " << seg.seg[j].second_mx;
      cout << " mx_num : " << seg.seg[j].mx_num;
      cout << " mi : " << seg.seg[j].mi;
      cout << " second_mi : " << seg.seg[j].second_mi;
      cout << " mi_num : " << seg.seg[j].mi_num;
      cout << " sum : " << seg.seg[j].sum;
      cout << " num : " << seg.seg[j].num;
      cout << " tag : " << seg.seg[j].tag;
      cout << endl;
    }
    */
  }
}

void AOJ_DSL_2_F(){
  int n,q;
  cin >> n >> q;
  vector<Data> vec(n,Data(2147483647));
  SegmentTreeBeats<Data> seg(vec,Data::merge);
  for(int i=0;i<q;i++){
    int type,l,r,x;
    cin >> type;
    if(type==0){
      cin >> l >> r >> x;
      seg.update(l,r+1,&Data::chmax_query,1000000000000ll);
      seg.update(l,r+1,&Data::chmin_query,x);
    }
    if(type==1){
      cin >> l >> r;
      cout << seg.query(l,r+1,&Data::get_min,[](ll x,ll y){return min(x,y);},LLINF) << endl;
    }
  }
}

void AOJ_DSL_2_G(){
  int n,q;
  cin >> n >> q;
  vector<Data> vec(n);
  SegmentTreeBeats<Data> seg(vec,Data::merge);
  for(int i=0;i<q;i++){
    int type,l,r,x;
    cin >> type;
    if(type==0){
      cin >> l >> r >> x;
      l--;
      seg.update(l,r,&Data::add,x);
    }
    if(type==1){
      cin >> l >> r;
      l--;
      cout << seg.query(l,r,&Data::get_sum,[](ll x,ll y){return x+y;},0ll) << endl;
    }
  }
}

void AOJ_DSL_2_I(){
  int n,q;
  cin >> n >> q;
  vector<Data> vec(n);
  SegmentTreeBeats<Data> seg(vec,Data::merge);
  for(int i=0;i<q;i++){
    int type,l,r,x;
    cin >> type;
    if(type==0){
      cin >> l >> r >> x;
      seg.update(l,r+1,&Data::chmax_query,2000);
      seg.update(l,r+1,&Data::chmin_query,x);
    }
    if(type==1){
      cin >> l >> r;
      cout << seg.query(l,r+1,&Data::get_sum,[](ll x,ll y){return x+y;},0ll) << endl;
    }
  }
}

signed main(){
  fastio();
  //yosupo_RangeChminChmaxAddRangeSum();
  AOJ_DSL_2_F();
  // AOJ_DSL_2_G();
  // AOJ_DSL_2_I();
  return 0;
}


Measured memory_bytes: 28520