#pragma GCC target ("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define _USE_MATH_DEFINES
#include<iostream>
#include<string>
#include<queue>
#include<cmath>
#include<map>
#include<set>
#include<list>
#include<iomanip>
#include<vector>
#include<random>
#include<functional>
#include<algorithm>
#include<stack>
#include<cstdio>
#include<cstring>
#include<bitset>
#include<unordered_map>
#include<climits>
#include<fstream>
#include<complex>
#include<time.h>
#include<cassert>
#include<functional>
#include<numeric>
#include<tuple>
using namespace std;
using ll = long long;
using ld = long double;
#define int long long
#define all(a) (a).begin(),(a).end()
#define fs first
#define sc second
#define xx first
#define yy second.first
#define zz second.second
#define H pair<int, int>
#define P pair<int, pair<int, int>>
#define Q(i,j,k) mkp(i,mkp(j,k))
#define rng(i,s,n) for(int i = (s) ; i < (n) ; i++)
#define rep(i,n) rng(i, 0, (n))
#define mkp make_pair
#define vec vector
#define pb emplace_back
#define crdcomp(b) sort(all((b)));(b).erase(unique(all((b))),(b).end())
#define getidx(b,i) lower_bound(all(b),(i))-b.begin()
#define ssp(i,n) (i==(int)(n)-1?"\n":" ")
#define ctoi(c) (int)(c-'0')
#define itoc(c) (char)(c+'0')
#define pp(x,y) pb(H{x,y})
#define ppp(x,y,z) pb(Q(x,y,z))
#define cyes printf("Yes\n")
#define cno printf("No\n")
#define cdf(n) int quetimes_=(n);rep(qq123_,quetimes_)
#define gcj printf("Case #%lld: ",qq123_+1)
#define readv(a,n) a.resize(n,0);rep(i,(n)) a[i]=read()
//#define endl "\n"
constexpr int mod = 1e9 + 7;
constexpr int Mod = 998244353;
constexpr int MXN = 500000 + 100;
constexpr ld EPS = 1e-10;
constexpr ll inf = 3 * 1e18;
constexpr int Inf = 15 * 1e8;
const vec<int>dx{ -1,1,0,0 }, dy{ 0,0,-1,1 };
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
ll read() { ll u, k = scanf("%lld", &u); return u; }
string reads() { string s; cin >> s; return s; }
H readh(bool g = 0) { H u; int k = scanf("%lld %lld", &u.fs, &u.sc); if (g) u.fs--, u.sc--; return u; }
bool inarea(H t, int h, int w) { return 0 <= t.fs && t.fs < h && 0 <= t.sc && t.sc < w; }
ll gcd(ll i, ll j) { return j ? gcd(j, i % j) : i; }
ll mod_pow(ll x, ll n, ll p = mod) {
	ll res = 1; x %= p;
	while (n > 0) {
		if (n & 1) res = res * x % p;
		x = x * x % p;
		n >>= 1;
	}
	return res;
}//x^n%p
ll bitcount(ll x) {
	int sum = 0; for (int i = 0; i < 60; i++)if ((1ll << i) & x) sum++;
	return sum;
}
constexpr int fn_ = 1000005;
ll fact_[fn_], comp_[fn_];
ll comb(ll x, ll y, ll Mod = mod) {
	if (!fact_[0]) {
		fact_[0] = 1; comp_[0] = 1;
		for (int i = 1; i < fn_; i++)
			fact_[i] = fact_[i - 1] * i % Mod;
		comp_[fn_ - 1] = mod_pow(fact_[fn_ - 1], Mod - 2, Mod);
		for (int i = fn_ - 2; i > 0; i--)
			comp_[i] = comp_[i + 1] * (i + 1) % Mod;
	}
	if (x < y) return 0;
	return fact_[x] * comp_[x - y] % Mod * comp_[y] % Mod;
}
//--------------------------------------------------------------
auto RUQ = [](int& num, int x, int width) {num = x; };
auto RAQ = [](int& num, int x, int width) {num += x; };
auto RCMXQ = [](int& num, int x, int width) {num = max(num, x); };
auto RCMNQ = [](int& num, int x, int width) {num = min(num, x); };
auto RASQ = [](int& num, int x, int width) {num += (x * width); };
auto RUSQ = [](int& num, int x, int width) {num = (x * width); };
auto RSQ = [](int x, int y)->int {return x + y; };
auto RMXQ = [](int x, int y)->int {return max(x, y); };
auto RMNQ = [](int x, int y)->int {return min(x, y); };
class Segtree {
#define DAT_SIZE 500000
	using F = function<void(int&, int, int)>;
	using T = function<int(int, int)>;
	int siz, rr, zer, zer2;
	int dat[DAT_SIZE], lazy[DAT_SIZE];
	bool updated[DAT_SIZE];
	F upd; T qur;
public:
	//for query, for update
	void init(int size, F update, T query, int zero, int zero2) {
		siz = size, upd = update, qur = query, zer = zero, zer2 = zero2;
		rr = 1; while (rr < size) rr *= 2;
		for (int i = 0; i < DAT_SIZE; i++) dat[i] = zer, lazy[i] = zer2, updated[i] = 0;
	}
	template<class Iterator>
	void build(const Iterator st, const Iterator ed) {
		Iterator it = st; int cur = rr - 1;
		while (it != ed) dat[cur++] = (*it++);
		for (int i = rr - 2; i >= 0; i--)
			dat[i] = qur(dat[i * 2 + 1], dat[i * 2 + 2]);
	}
	void build(vector<int>v) {
		for (int i = 0; i < min((int)v.size(), siz); i++)
			dat[i + rr - 1] = v[i];
		for (int i = rr - 2; i >= 0; i--)
			dat[i] = qur(dat[i * 2 + 1], dat[i * 2 + 2]);
	}
	void update(int a, int b, int x) {
		update(0, a, b, 0, rr, x);
	}
	int query(int a, int b) {
		return query(0, a, b, 0, rr);
	}
	int lower_bound(int a, int b, function<bool(int)>comp) {
		return lower_bound(0, a, b, 0, rr, comp);
	}
	int upper_bound(int a, int b, function<bool(int)>comp) {
		return upper_bound(0, a, b, 0, rr, comp);
	}
	int operator[](const int i) {
		return query(i, i + 1);
	}
private:
	void eval(int i, int l, int r) {
		if (!updated[i]) return;
		if (r - l > 1) {
			upd(lazy[i * 2 + 1], lazy[i], 1);
			upd(lazy[i * 2 + 2], lazy[i], 1);
			updated[i * 2 + 1] = updated[i * 2 + 2] = 1;
		}
		upd(dat[i], lazy[i], min(r, siz) - l);
		lazy[i] = zer2;
		updated[i] = 0;
	}
	void update(int i, int a, int b, int l, int r, int x) {
		eval(i, l, r);
		if (b <= l || r <= a) return;
		if (a <= l && r <= b) {
			upd(lazy[i], x, 1); updated[i] = 1;
			eval(i, l, r);
			return;
		}
		update(i * 2 + 1, a, b, l, (l + r) / 2, x);
		update(i * 2 + 2, a, b, (l + r) / 2, r, x);
		dat[i] = qur(dat[i * 2 + 1], dat[i * 2 + 2]);
	}
	int query(int i, int a, int b, int l, int r) {
		eval(i, l, r);
		if (b <= l || r <= a) return zer;
		if (a <= l && r <= b) return dat[i];
		return qur(query(i * 2 + 1, a, b, l, (l + r) / 2),
			query(i * 2 + 2, a, b, (l + r) / 2, r));
	}
	int lower_bound(int i, int a, int b, int l, int r, function<bool(int)>comp) {
		eval(i, l, r);
		if (b <= l || r <= a || !comp(dat[i])) return siz;
		if (r - l == 1) return l;
		int tmp = lower_bound(i * 2 + 1, a, b, l, (l + r) / 2, comp);
		if (tmp < siz) return tmp;
		return lower_bound(i * 2 + 2, a, b, (l + r) / 2, r, comp);
	}
	int upper_bound(int i, int a, int b, int l, int r, function<bool(int)>comp) {
		eval(i, l, r);
		if (b <= l || r <= a || !comp(dat[i])) return 0;
		if (r - l == 1) return r;
		int tmp = upper_bound(i * 2 + 2, a, b, (l + r) / 2, r, comp);
		if (tmp > 0) return tmp;
		return upper_bound(i * 2 + 1, a, b, l, (l + r) / 2, comp);
	}
};
Segtree seg;
signed main() {
	int n, q; cin >> n >> q;
	seg.init(n, RUQ, RMNQ, inf, 0);
	seg.build(vec<int>(n, (1ll << 31) - 1));
	rep(i, q) {
		int a, s, t, x;
		cin >> a >> s >> t;
		t++;
		if (a == 0) {
			cin >> x;
			seg.update(s, t, x);
		}
		else {
			cout << seg.query(s, t) << endl;
		}
	}
}


Measured memory_bytes: 11884