#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/numeric/interval.hpp>
#include <boost/numeric/interval/io.hpp>
#include <boost/any.hpp>
using namespace::std;
namespace mp = boost::multiprecision;
typedef mp::number<mp::cpp_dec_float<32,int64_t>> cfloat;
typedef mp::cpp_int cint;
typedef long long lint;
typedef long long ll;
typedef long double ldouble;
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
typedef vector<vector<vector<lint>>> mat3;
typedef vector<double> dvec;
typedef vector<vector<double>> dmat;
typedef vector<vector<vector<double>>> dmat3;
typedef vector<string> svec;
typedef vector<vector<string>> smat;
typedef vector<vector<vector<string>>> smat3;
typedef vector<pair<lint,lint>> pvec;
typedef vector<vector<pair<lint,lint>>> pmat;
typedef vector<vector<vector<pair<lint,lint>>>> pmat3;
#define rep(i, n) for(lint i = 0; i < (lint)(n); i++)
#define irep(i) for(lint i = 0;; i++)
#define irep1(i) for(lint i = 1;; i++)
#define irep2(i) for(lint i = 2;; i++)
#define rrep(i, n) for(lint i = (lint)(n-1); i >-1; i--)
#define rrepi(i,a,b) for(lint i = (lint)(b-1); i >a-1; i--)
#define repi(i,a,b) for(lint i=lint(a);i<lint(b);i++)
#define rep2(i,a,b,c) for(lint i=lint(a);i>lint(b);i+=c)
#define all(x) (x).begin(),(x).end()
#define PI 3.141592653589793
#define cout (cout<<fixed<<setprecision(15))
#define dist(x1,y1,x2,y2) (pow(pow(x2-x1,2)+pow(y2-y1,2),0.5))
#define output(v) do{bool f=0;for(auto i:v){cout<<(f?" ":"")<<i;f=1;}cout<<"\n";}while(0)
#define output2(v) for(auto i:v)output(i);
#define input(a,n) lint n;cin>>n;vector<lint>a(n);rep(i,n)cin>>a[i];
#define sum(v) accumulate(all(v),0LL)
#define INF (1LL<<60)
#define IINF (1<<30)
#define LINF 9223372036854775807
#define MOD 1000000007
vector<lint> dx={-1,1,0,0,1,1,-1,-1};
vector<lint> dy={0,0,-1,1,1,-1,1,-1};
inline lint gcd(lint a,lint b){return b?gcd(b,a%b):a;}
inline lint lcm(lint a,lint b){return a*b/gcd(a,b);}
template<typename T,typename E>struct LSEG{
    lint n=1;
    vector<T> node;
    vector<E> lazy;
    T et;
    E ee;
    LSEG(lint size,T et,E ee):et(et),ee(ee){
        while(n<size)n<<=1;
        node.resize(2*n-1,et);
        lazy.resize(2*n-1,ee);
    }
    inline void eval(lint k,lint len){
        if(lazy[k]==ee) return;
        if(k*2+1<n*2-1){
            lazy[k*2+1]=g(lazy[k*2+1],lazy[k]);
            lazy[k*2+2]=g(lazy[k*2+2],lazy[k]);
        }
        node[k]=h(node[k],lazy[k],len);
        lazy[k]=ee;
    }

    //0-indexed [a,b)
    T update(lint a,lint b,E x,lint k=0,lint l=0,lint r=-1){
        if(r<0)r=n;
        eval(k,r-l);
        //区間外
        if(r<=a||b<=l)return node[k];
        //全部区間内
        if(a<=l&&r<=b){
            lazy[k]=g(lazy[k],x);
            return h(node[k],lazy[k],r-l);
        }
        //一部区間内
        return node[k]=f(update(a,b,x,2*k+1,l,(l+r)/2),update(a,b,x,2*k+2,(l+r)/2,r));
    }
    //0-indexed [a,b)
    T get(lint a,lint b,lint k=0,lint l=0,lint r=-1){
        if(r<0)r=n;
        eval(k,r-l);
        //区間外
        if(r<=a||b<=l)return et;
        //全部区間内
        if(a<=l&&r<=b)return node[k];
        //一部区間内
        return f(get(a,b,2*k+1,l,(l+r)/2),get(a,b,2*k+2,(l+r)/2,r));
    }
    T f(T a,T b){
        return min(a,b);
    }
    T h(T a,E b,lint len){
        if(b==-1)return a;
        else return b;
    }
    E g(E a,E b){
        return b;
    }
};
int main(){
    lint n,q;
    cin>>n>>q;
    LSEG<lint,lint> seg=LSEG<lint,lint>(n,(1LL<<31)-1,-1);
    rep(i,q){
        lint query;
        cin>>query;
        if(query==0){
            lint s,t,x;
            cin>>s>>t>>x;
            seg.update(s,t+1,x);
        }else{
            lint s,t;
            cin>>s>>t;
            cout<<seg.get(s,t+1)<<endl;
        }
    }
}


Measured memory_bytes: 7092