// need
#include <iostream>
#include <algorithm>

// data structure
#include <bitset>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
//#include <complex>
//#include <deque>
#include <valarray>

// stream
//#include <istream>
//#include <sstream>
//#include <ostream>
#include <fstream>

// etc
#include <cassert>
#include <cmath>
#include <functional>
#include <iomanip>
#include <chrono>
#include <random>
#include <numeric>

// input
#define INIT std::ios::sync_with_stdio(false);std::cin.tie(0);
#define VAR(type, ...)type __VA_ARGS__;MACRO_VAR_Scan(__VA_ARGS__);
template<typename T> void MACRO_VAR_Scan(T& t) { std::cin >> t; }
template<typename First, typename...Rest>void MACRO_VAR_Scan(First& first, Rest&...rest) { std::cin >> first; MACRO_VAR_Scan(rest...); }
#define VEC_ROW(type, n, ...)std::vector<type> __VA_ARGS__;MACRO_VEC_ROW_Init(n, __VA_ARGS__); for(int i=0; i<n; ++i){MACRO_VEC_ROW_Scan(i, __VA_ARGS__);}
template<typename T> void MACRO_VEC_ROW_Init(int n, T& t) { t.resize(n); }
template<typename First, typename...Rest>void MACRO_VEC_ROW_Init(int n, First& first, Rest&...rest) { first.resize(n); MACRO_VEC_ROW_Init(n, rest...); }
template<typename T> void MACRO_VEC_ROW_Scan(int p, T& t) { std::cin >> t[p]; }
template<typename First, typename...Rest>void MACRO_VEC_ROW_Scan(int p, First& first, Rest&...rest) { std::cin >> first[p]; MACRO_VEC_ROW_Scan(p, rest...); }
#define VEC(type, c, n) std::vector<type> c(n);for(auto& i:c)std::cin>>i;
#define MAT(type, c, m, n) std::vector<std::vector<type>> c(m, std::vector<type>(n));for(auto& r:c)for(auto& i:r)std::cin>>i;

// output
#define OUT(d) std::cout<<(d);
#define FOUT(n, d) std::cout<<std::fixed<<std::setprecision(n)<<(d);
#define SOUT(n, c, d) std::cout<<std::setw(n)<<std::setfill(c)<<(d);
#define SP std::cout<<" ";
#define TAB std::cout<<"\t";
#define BR std::cout<<"\n";
#define SPBR(i, n) std::cout<<(i + 1 == n ? '\n' : ' ');
#define ENDL std::cout<<std::endl;
#define FLUSH std::cout<<std::flush;
#define SHOW(d) {std::cerr << #d << "\t:" << (d) << "\n";}
#define SHOWVECTOR(v) {std::cerr << #v << "\t:";for(const auto& xxx : v){std::cerr << xxx << " ";}std::cerr << "\n";}
#define SHOWVECTOR2(v) {std::cerr << #v << "\t:\n";for(const auto& xxx : v){for(const auto& yyy : xxx){std::cerr << yyy << " ";}std::cerr << "\n";}}
#define SHOWQUEUE(a) {auto tmp(a);std::cerr << #a << "\t:";while(!tmp.empty()){std::cerr << tmp.front() << " ";tmp.pop();}std::cerr << "\n";}

// utility
#define ALL(a) (a).begin(),(a).end()
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define RFOR(i, a, b) for(int i=(b)-1;i>=(a);--i)
#define REP(i, n) for(int i=0;i<int(n);++i)
#define RREP(i, n) for(int i=int(n)-1;i>=0;--i)
#define FORLL(i, a, b) for(ll i=ll(a);i<ll(b);++i)
#define RFORLL(i, a, b) for(ll i=ll(b)-1;i>=ll(a);--i)
#define REPLL(i, n) for(ll i=0;i<ll(n);++i)
#define RREPLL(i, n) for(ll i=ll(n)-1;i>=0;--i)
#define IN(a, x, b) (a<=x && x<b)
template<typename T> inline T CHMAX(T& a, const T b) { return a = (a < b) ? b : a; }
template<typename T> inline T CHMIN(T& a, const T b) { return a = (a > b) ? b : a; }
#define EXCEPTION(msg) throw std::string("Exception : " msg " [ in ") + __func__ + " : " + std::to_string(__LINE__) + " lines ]"
#define TRY(cond, msg) try {if (cond) EXCEPTION(msg);}catch (std::string s) {std::cerr << s << std::endl;}
void CHECKTIME(std::function<void()> f) { auto start = std::chrono::system_clock::now(); f(); auto end = std::chrono::system_clock::now(); auto res = std::chrono::duration_cast<std::chrono::nanoseconds>((end - start)).count(); std::cerr << "[Time:" << res << "ns  (" << res / (1.0e9) << "s)]\n"; }

// test
template<class T> std::vector<std::vector<T>> VV(int n, int m, T init = T()) {
	return std::vector<std::vector<T>>(n, std::vector<T>(m, init));
}
template<typename S, typename T>
std::ostream& operator<<(std::ostream& os, std::pair<S, T> p) {
	os << "(" << p.first << ", " << p.second << ")"; return os;
}

// type/const
#define int ll
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using PAIR = std::pair<int, int>;
using PAIRLL = std::pair<ll, ll>;
constexpr int INFINT = 1 << 30;                          // 1.07x10^ 9
constexpr int INFINT_LIM = (1LL << 31) - 1;              // 2.15x10^ 9
constexpr ll INFLL = 1LL << 60;                          // 1.15x10^18
constexpr ll INFLL_LIM = (1LL << 62) - 1 + (1LL << 62);  // 9.22x10^18
constexpr double EPS = 1e-9;
constexpr int MOD = 1000000007;
constexpr double PI = 3.141592653589793238462643383279;

template<class T, size_t N> void FILL(T(&a)[N], const T& val) { for (auto& x : a) x = val; }
template<class ARY, size_t N, size_t M, class T> void FILL(ARY(&a)[N][M], const T& val) { for (auto& b : a) FILL(b, val); }
template<class T> void FILL(std::vector<T>& a, const T& val) { for (auto& x : a) x = val; }
template<class ARY, class T> void FILL(std::vector<std::vector<ARY>>& a, const T& val) { for (auto& b : a) FILL(b, val); }

// ------------>8------------------------------------->8------------


// write [ StarrySkyTree<> sst(n) ] when using this snippet.
template<typename T = ll, bool QUERY_IS_GETMAX = true>
struct StarrySkyTree {
	std::vector<T> seg, laz;
	int size;
	T inf;
	std::function<T(T&, T&)> func;
	StarrySkyTree() {}
	StarrySkyTree(int n) : inf((QUERY_IS_GETMAX ? std::numeric_limits<T>::min() : std::numeric_limits<T>::max())), func([](T& a, T& b) {return (QUERY_IS_GETMAX ? std::max(a, b) : std::min(a, b)); }) {
		init(n);
	}
	void init(int n) {
		size = 1;
		while (size < n) size *= 2;
		seg.resize(size * 2);
		laz.resize(size * 2);
	}
	void push(int k, int l, int r) {
		seg[k] += laz[k];
		if (r - l > 1) {
			laz[k * 2 + 1] += laz[k];
			laz[k * 2 + 2] += laz[k];
		}
		laz[k] = 0;
	}
	void update(int a, int b, T v, int k, int l, int r) {
		push(k, l, r);
		if (r <= a || b <= l) return;
		if (a <= l && r <= b) {
			laz[k] += v;
			push(k, l, r);
		}
		else {
			update(a, b, v, k * 2 + 1, l, (l + r) / 2);
			update(a, b, v, k * 2 + 2, (l + r) / 2, r);
			seg[k] = func(seg[k * 2 + 1], seg[k * 2 + 2]);

		}
	}
	// add v to [a,b)
	void update(int a, int b, T v) {
		update(a, b, v, 0, 0, size);
	}
	T query(int a, int b, int k, int l, int r) {
		push(k, l, r);
		if (r <= a || b <= l) return inf;
		if (a <= l && r <= b) return seg[k];
		T vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
		T vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
		return func(vl, vr);
	}
	// return min(or max) in [a,b)
	T query(int a, int b) {
		return query(a, b, 0, 0, size);
	}
};

// ------------>8---------- LazySegmentTree ---------->8------------

// write [ LazySegmentTree st(n, SUM/MAX/MIN, ADD/UPD) ] when using this snippet.
enum QUERY_SEG_LazySegmentTree { SUM, MAX, MIN };
enum QUERY_LAZ_LazySegmentTree { ADD, UPD };
template<class SEG, class LAZ>
class LazySegmentTree {
private:
	std::vector<SEG> seg;
	std::vector<LAZ> laz;
	std::vector<bool> isUpdated;
	int ARY_SIZE;
	SEG eSeg;
	LAZ eLaz;
	std::function<SEG(SEG&, SEG&)> mergeSeg;
	std::function<LAZ(LAZ&, LAZ&)> mergeLaz;
	std::function<SEG(SEG&, LAZ&, int)> applyLaz;

	void push(int k, int l, int r) {
		if (!isUpdated[k]) {
			seg[k] = applyLaz(seg[k], laz[k], r - l);
			if (r - l > 1) {
				mergeLaz(laz[k * 2 + 1], laz[k]); isUpdated[k * 2 + 1] = false;
				mergeLaz(laz[k * 2 + 2], laz[k]); isUpdated[k * 2 + 2] = false;
			}
			isUpdated[k] = true;
			laz[k] = eLaz;
		}
	}
public:
	LazySegmentTree(int n, QUERY_SEG_LazySegmentTree qSeg, QUERY_LAZ_LazySegmentTree qLaz) : ARY_SIZE(1) {
		ARY_SIZE = 1;
		while (ARY_SIZE < n) ARY_SIZE *= 2;
		seg.resize(ARY_SIZE * 2 - 1);
		laz.resize(ARY_SIZE * 2 - 1);
		isUpdated.resize(ARY_SIZE * 2 - 1, true);

		switch (qSeg) {
			case SUM:
				eSeg = 0;
				mergeSeg = [](SEG& l, SEG& r) { return l + r; };
				break;
			case MAX:
				eSeg = std::numeric_limits<SEG>::lowest();
				mergeSeg = [](SEG& l, SEG& r) { return std::max(l, r); };
				break;
			case MIN:
				eSeg = std::numeric_limits<SEG>::max();
				mergeSeg = [](SEG& l, SEG& r) { return std::min(l, r); };
				break;
			default:
				struct INVALID_QUERY_TYPE_ERROR {};
				throw INVALID_QUERY_TYPE_ERROR();
				break;
		}

		switch (qLaz)
		{
			case ADD:
				eLaz = 0;
				mergeLaz = [](LAZ& l, LAZ& r) { return l += r; };
				if (qSeg == SUM) applyLaz = [](SEG& s, LAZ& l, int w) { return s += l * w; };
				else applyLaz = [](SEG& s, LAZ& l, int w) { return s += l; };
				break;
			case UPD:
				eLaz = 0;
				mergeLaz = [](LAZ& l, LAZ& r) { return l = r; };
				if (qSeg == SUM) applyLaz = [](SEG& s, LAZ& l, int w) { return s = l * w; };
				else applyLaz = [](SEG& s, LAZ& l, int w) { return s = l; };
				break;
			default:
				struct INVALID_QUERY_TYPE_ERROR {};
				throw INVALID_QUERY_TYPE_ERROR();
				break;
		}
	}
	void update(int a, int b, SEG v, int k, int l, int r) {
		push(k, l, r);
		if (r <= a || b <= l) return;
		if (a <= l && r <= b) {
			LAZ la(v);
			mergeLaz(laz[k], la);
			isUpdated[k] = false;
			push(k, l, r);
		}
		else {
			update(a, b, v, k * 2 + 1, l, (l + r) / 2);
			update(a, b, v, k * 2 + 2, (l + r) / 2, r);
			seg[k] = mergeSeg(seg[k * 2 + 1], seg[k * 2 + 2]);
		}
	}
	// add v to [a,b)
	void update(int a, int b, SEG v) {
		update(a, b, v, 0, 0, ARY_SIZE);
	}
	SEG query(int a, int b, int k, int l, int r) {
		push(k, l, r);
		if (r <= a || b <= l) return eSeg;
		if (a <= l && r <= b) return seg[k];
		SEG vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
		SEG vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
		return mergeSeg(vl, vr);
	}
	// return min(or max) in [a,b)
	SEG query(int a, int b) {
		return query(a, b, 0, 0, ARY_SIZE);
	}
};

using LST = LazySegmentTree<ll, ll>;
// ------------>8---------- LazySegmentTree ---------->8------------

signed main() {
	INIT;

	VAR(int, n, Q);

	LST lst(n, MIN, UPD);
	REP(i, n) lst.update(0, n, (1 << 30) - 1 + (1 << 30));
	REP(_, Q) {
		VAR(int, c, s, t);
		if (c == 0) {
			VAR(int, x);
			lst.update(s, t + 1, x);
		}
		else {
			OUT(lst.query(s, t + 1))BR;
		}
	}

	return 0;
}



Measured memory_bytes: 7224