#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> P;
typedef pair<int,int> Pi;
#define rep(i,n) for(ll i=0;i<n;i++)
#define FOR(i,a,b) for(ll i=a;i<b;i++)
#define fi first
#define se second
#define endl "\n"

template<typename T> inline bool chmax(T &a, T b){if(a<b){a=b;return true;}return false;}
template<typename T> inline bool chmin(T &a, T b){if(a>b){a=b;return true;}return false;}
template<typename T> ostream& operator<<(ostream& s,const complex<T>& d) {return s<<"("<<d.real()<<", "<<d.imag()<< ")";}
template<typename T1, typename T2> ostream& operator<<(ostream& s,const pair<T1,T2>& d) {return s<<"("<<d.first<<", "<<d.second<<")";}
template<typename T> ostream& operator<<(ostream& s, const vector<T>& d){int len=d.size();rep(i,len){s<<d[i];if(i<len-1) s<<" ";}return s;}
template<typename T> ostream& operator<<(ostream& s,const vector<vector<T>>& d){int len=d.size();rep(i,len){s<<d[i]<<endl;}return s;}
template<typename T> ostream& operator<<(ostream& s,const set<T>& v){s<<"{ ";for(auto itr=v.begin();itr!=v.end();++itr) {if (itr!=v.begin()) {s<< ", ";}s<<(*itr);}s<<" }";return s;}
template<typename T1, typename T2> ostream& operator<<(ostream& s,const map<T1,T2>& m){s<<"{"<<endl;for(auto itr=m.begin();itr!=m.end();++itr){s<<" "<<(*itr).first<<" : "<<(*itr).second<<endl;}s<<"}"<<endl;return s;}

const ll mod=1e9+7;
const ll inf=(1ll<<31)-1;
const int INF=1e9;
const double PI=acos(-1);
const double EPS=1e-10;

//遅延評価セグメントツリー
//http://tsutaj.hatenablog.com/entry/2017/03/30/224339#f-8a40ea86
//ここにパターンごとのcodeがのっています
//区間更新、区間最小
struct LazySegmentTree{
private:
    int n;
    ll I=inf;
    vector<ll> node,lazy;
    vector<bool> lazyFlag;
 
public:
    LazySegmentTree(){
        int sz=100050;
        n=1;
		while(n < sz) n*=2;
        node.resize(2*n-1,I);
        lazy.resize(2*n-1,I);
        lazyFlag.resize(2*n-1,false);
 
        for(int i=0;i<sz;i++) node[i+n-1]=I;
        for(int i=n-2;i>=0;i--) node[i]=min(node[i*2+1],node[i*2+2]);
    }
	//k番目のノードについて遅延評価を行う
    void lazyEvaluate(int k,int l,int r){
		//遅延配列が空で無い場合、自ノード及子ノードへの値の伝搬
        if(lazyFlag[k]){
            node[k]=lazy[k];
			//最下段かどうかのチェック
            if(r-l>1) {
                lazy[k*2+1]=lazy[k];
                lazy[k*2+2]=lazy[k];
                lazyFlag[k*2+1]=lazyFlag[k*2+2]=true;
            }
			//自ノードを初期化
            lazyFlag[k]=false;
            lazy[k]=I;
        }
    }
 
    void update(int a,int b,ll x,int k=0,int l=0,int r=-1){
        if(r<0) r=n;
        lazyEvaluate(k,l,r);//kノードに対し遅延評価
        if(b<=l || r<=a) return;
        if(a<=l && r<=b) {
            lazy[k]=x;
            lazyFlag[k]=true;
            lazyEvaluate(k,l,r);
        }
        else{
            update(a,b,x,2*k+1,l,(l+r)/2);
            update(a,b,x,2*k+2,(l+r)/2,r);
            node[k]=min(node[2*k+1],node[2*k+2]);
        }
    }
 
    ll getmin(int a, int b, int k=0, int l=0, int r=-1) {
        if(r < 0) r = n;
        lazyEvaluate(k, l, r);
        if(b <= l || r <= a) return I;
        if(a <= l && r <= b) return node[k];
        ll vl = getmin(a, b, 2*k+1, l, (l+r)/2);
        ll vr = getmin(a, b, 2*k+2, (l+r)/2, r);
        return min(vl, vr);
    }
};

int main(){
	cin.tie(0);ios::sync_with_stdio(false);
	ll n,q;
	cin>>n>>q;
	vector<ll> a(n,inf);
	LazySegmentTree seg;
	while(q--){
		int c;
		cin>>c;
		int s,t;
		cin>>s>>t;
		if(c){
			cout<<seg.getmin(s,t+1)<<endl;
		}else{
			ll x;
			cin>>x;
			seg.update(s,t+1,x);
		}
        //cout<<seg.getmin(0,1)<<' '<<seg.getmin(1,2)<<' '<<seg.getmin(2,3)<<endl;
	}
}


Measured memory_bytes: 7932