// see https://gist.github.com/LumaKernel/ff55d49ee1af69b7388f15b707e75c15
const bool DEBUG = 1;
#include <iostream>
#include <vector>
#include <array>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <tuple>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <complex>
#include <random>
#include <iomanip>
#include <cassert>
#include <functional>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef tuple<ll, ll> P;
typedef tuple<ll, ll, ll> P3;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef vector<P> VP;
typedef vector<string> VS;

#define omajinai ios::sync_with_stdio(false);cin.tie(0)

#define FOR(i,a,b) for(int i=int(a);i<int(b);++i)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,a,b) for(int i=int(b)-1;i>=int(a);--i)
#define RREP(i,n) RFOR(i,0,n)

#define ALL(a) (a).begin(),(a).end()
#define UNIQUE(a) (a).erase(unique(ALL(a)),(a).end())
#define EACH(i,c) REP(i,(c).size())
#define REACH(i,c) RREP(i,(c).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort(ALL(c))

#define BR cout<<"\n"

#define dump(x) if(DEBUG) cerr<<"["<<__LINE__<< "] "<<#x<<"="<<(x)<<"\n"
#define dump2(x,y) if(DEBUG) cerr<<"["<<__LINE__<< "] "<<#x<<"="<<(x)\
  <<" , "<<#y<<"="<<(y)<<"\n"
#define dump3(x,y,z) if(DEBUG)cerr<<"["<<__LINE__<<"] "<<#x<<"="<<(x)\
  <<" , "<<#y<<"="<<(y)<<"\n"\
  <<" , "<<#z<<"="<<(z)<<"\n"

#define SAY(x) if(DEBUG) cerr<<"["<<__LINE__<< "] "<<(x)<<"\n"

#define YES(x) cout<<((x)?"YES":"NO")<<"\n"
#define Yes(x) cout<<((x)?"Yes":"No")<<"\n"
#define yes(x) cout<<((x)?"yes":"no")<<"\n"

inline int omajinai_int_in(){omajinai;int n;cin>>n;return n;}
inline ll omajinai_ll_in(){omajinai;ll n;cin>>n;return n;}
inline string omajinai_string_in(){omajinai;string n;cin>>n;return n;}
inline int int_in(){int n;cin>>n;return n;}
inline ll ll_in(){ll n;cin>>n;return n;}
inline string string_in(){string n;cin>>n;return n;}
#define oini omajinai_int_in()
#define oinl omajinai_ll_in()
#define oins omajinai_string_in()
#define ini int_in()
#define inl ll_in()
#define ins string_in()

#define isInside(x,y) (0<=(x)&&(x)<w&&0<=(y)&&(y)<h)

#define fi(x) (get<0>(x))
#define se(x) (get<1>(x))
#define th(x) (get<2>(x))
#define fo(x) (get<3>(x))

constexpr int INF = 1e9+1;
constexpr ll LINF = 1e18+1;
constexpr int MOD = 1e9+7;

template <typename T> ostream &operator<<(ostream &o, const vector<T> &v) { o << '['; EACH(i, v) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]";  return o; }

template <typename T> function<T(T,T)> constexpr mmin(){ return [](T x, T y){return x<y?x:y;}; }
template <typename T> function<T(T,T)> constexpr mmax(){ return [](T x, T y){return x>y?x:y;}; }
template <typename T> function<T(T,T)> constexpr madd(){ return [](T x, T y){return x+y;}; }
template <typename T> function<T(T,T)> constexpr modadd(){ return [](T x, T y){return ((x+y)%MOD+MOD)%MOD;}; }

ll ans;
const int def = (1ll<<31) - 1;
const int N = 1e5+1;

struct LazySegTree {
	int data[N*4];
	int lazy[N*4];
	int m=0;
	void init(int n) {
		m=1;
		while(m<n) m<<=1;
		REP(i, m*2-1) {
			data[i] = def;
			lazy[i] = -1;
		}
	}
	void eval(int k, int l, int r) {
		if(lazy[k]<0) return;
		data[k] = lazy[k];
		if(r-l>1) {
			lazy[k*2+1] = lazy[k*2+2] = lazy[k];
		}
		lazy[k] = -1;
	}
	void update(int a, int b, int x, int k = 0, int l = 0, int r = -1) {
		if(r<0) r = m;
		eval(k, l, r);
		if(b<=l||r<=a) return;
		// O(1)
		if(a<=l&&r<=b) {
			lazy[k] = x;
			eval(k, l, r);
			return;
		}
		update(a, b, x, k*2+1, l, (l+r)/2); //////////////////
		update(a, b, x, k*2+2, (l+r)/2, r); //////////////////
		data[k] = min(data[k*2+1], data[k*2+2]);
	}
	int mini(int a, int b, int k = 0, int l = 0, int r = -1) {
		if(r<0) r = m;
		eval(k, l, r);
		if(b<=l||r<=a) return def;
		if(a<=l&&r<=b) {
			return data[k];
		}
		return min(
			mini(a, b, k*2+1, l, (l+r)/2),
			mini(a, b, k*2+2, (l+r)/2, r)
		);
	}
};

LazySegTree tree;
int main() {
	//#####//
	int n=ini, q=ini;
	tree.init(n+1);
	REP(i, q) {
		int type=ini, s=ini, t=ini;
		int x;
		switch(type) {
		case 0:
			x = ini;
			tree.update(s, t+1, x);
			break;
		case 1:
			cout<<tree.mini(s, t+1)<<endl;
			break;
		}
	}
}

//

Measured memory_bytes: 5164