#include <iostream>
#include <algorithm>
#include <array>
#include <cstdint>
#include <functional>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stack>
#include <stdlib.h>
#include <string>
#include <time.h>
#include <utility>
#include <vector>

#define INF 1000000000
#define MOD 1000000007
#define rep(i,a,b) for(uint32 i = (a); i < (b); ++i)
#define bitget(a,b) (((a) >> (b)) & 1)
#define ALL(x) (x).begin(),(x).end()
#define C(x) std::cout << #x << " : " << x << std::endl
#define scanf scanf_s

using int32 = std::int_fast32_t;
using int64 = std::int_fast64_t;
using uint32 = std::uint_fast32_t;
using uint64 = std::uint_fast64_t;

#include <iostream>
#include <algorithm>
#include <array>
#include <cstdint>
#include <functional>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stack>
#include <stdlib.h>
#include <string>
#include <time.h>
#include <utility>
#include <vector>

#define INF 1000000000
#define MOD 1000000007
#define rep(i,a,b) for(uint32 i = (a); i < (b); ++i)
#define bitget(a,b) (((a) >> (b)) & 1)
#define ALL(x) (x).begin(),(x).end()
#define C(x) std::cout << #x << " : " << x << std::endl
#define scanf scanf_s

using int32 = std::int_fast32_t;
using int64 = std::int_fast64_t;
using uint32 = std::uint_fast32_t;
using uint64 = std::uint_fast64_t;
template<typename Monoid, typename Operand>
struct RBnode {
	RBnode *ch[2], *par;
	Monoid value, sum;
	Operand lazy;
	uint32 size, height;
	bool color, reversed;//true=black
};
template<typename Monoid, typename Operand>
class RBTrees {
	using Node = RBnode<Monoid, Operand>;
	std::vector<Node> nodes;
	uint32 itr;
	bool balanced;
	Node *backup;
public:
	RBTrees(size_t maxsize) {
		nodes.resize(maxsize + 1);
		itr = 0;
		nodes[0].ch[0] = &nodes[0];
		nodes[0].ch[1] = &nodes[0];
		nodes[0].par = nullptr;
		nodes[0].size = 0;
		nodes[0].height = 1;
		nodes[0].color = 1;
	}
	Node *nil(void) {
		return &nodes[0];
	}
	Node *recalc(Node *node) {
		node->sum = node->value;
		if (node->ch[0] != &nodes[0]) {
			node->sum = node->ch[0]->sum + node->sum;
		}
		if (node->ch[1] != &nodes[0]) {
			node->sum = node->sum + node->ch[1]->sum;
		}
		node->size = node->ch[0]->size + 1 + node->ch[1]->size;
		return node;
	}
	void push(Node *node) {
		node->ch[0]->lazy = node->ch[0]->lazy * node->lazy;
		node->ch[1]->lazy = node->ch[1]->lazy * node->lazy;
		node->value = node->value * node->lazy;
		node->sum = node->sum * node->lazy;
		node->lazy.inactive();
		if (node->reversed) {
			node->ch[0]->reversed ^= 1;
			node->ch[1]->reversed ^= 1;
			std::swap(node->ch[0], node->ch[1]);
			node->sum.reverse();
			node->value.reverse();
			node->reversed = 0;
		}
		return;
	}
	Node *rotate(Node *node, uint32 dir) {
		Node *t = node->ch[dir ^ 1];
		node->ch[dir ^ 1] = t->ch[dir];
		t->ch[dir]->par = node;
		node->height = t->ch[dir]->height;
		t->height = node->height + node->color;
		t->color = node->color;
		node->color = 0;
		t->par = node->par;
		node->par = t;
		t->ch[dir] = recalc(node);
		return recalc(t);
	}
	Node *insert(Node *root, const Monoid &value, uint32 position) {
		nodes[++itr].ch[0] = &nodes[0];
		nodes[itr].ch[1] = &nodes[0];
		nodes[itr].value = value;
		nodes[itr].sum = value;
		nodes[itr].lazy.inactive();
		nodes[itr].size = 1;
		nodes[itr].height = 1;
		nodes[itr].color = 0;
		nodes[itr].reversed = 0;
		backup = nullptr;
		push(root);
		root = _subinsert(root, position);
		if (!root->color) {
			root->height += 1;
			root->color = 1;
		}
		return root;
	}
	Node *_subinsert(Node *node, uint32 pos) {
		if (node == &nodes[0]) {
			balanced = 1;
			nodes[itr].par = backup;
			return &nodes[itr];
		}
		backup = node;
		push(node->ch[0]);
		push(node->ch[1]);
		if (node->ch[0]->size < pos) {
			node->ch[1] = _subinsert(node->ch[1], pos - node->ch[0]->size - 1);
			if (balanced) {
				return _insertadjust(node, 1);
			}
		}
		else {
			node->ch[0] = _subinsert(node->ch[0], pos);
			if (balanced) {
				return _insertadjust(node, 0);
			}
		}
		return recalc(node);
	}
	Node *_insertadjust(Node *node, uint32 dir) {
		if (!node->color) {
			return recalc(node);
		}
		if (!node->ch[dir ^ 1]->color) {
			if (node->ch[dir]->ch[dir]->color&&node->ch[dir]->ch[dir ^ 1]->color) {
				balanced = 0;
				return recalc(node);
			}
			return flip(recalc(node));
		}
		balanced = 0;
		if (node->ch[dir]->ch[dir]->color) {
			if (node->ch[dir]->ch[dir ^ 1]->color) {
				return recalc(node);
			}
			else {
				node->ch[dir] = rotate(node->ch[dir], dir);
				return rotate(node, dir ^ 1);
			}
		}
		else {
			if (node->ch[dir]->ch[dir ^ 1]->color) {
				return rotate(node, dir ^ 1);
			}
			else {
				node->ch[dir] = rotate(node->ch[dir], dir);
				balanced = 1;
				node = rotate(node, dir ^ 1);
				return flip(node);
			}
		}
	}
	Node *flip(Node *node) {
		node->ch[0]->color = 1;
		node->ch[0]->height += 1;
		node->ch[1]->color = 1;
		node->ch[1]->height += 1;
		node->color = 0;
		return node;
	}
	Node *access(Node *root, uint32 position) {
		while (root->ch[0]->size != position) {
			if (position > root->ch[0]->size) {
				position -= root->ch[0]->size + 1;
				root = root->ch[1];
			}
			else {
				root = root->ch[0];
			}
		}
		return root;
	}
	Node *erase(Node *root, uint32 position) {
		push(root);
		return _suberase(root, position);
	}
	Node *_suberase(Node *node, uint32 position) {
		push(node->ch[0]);
		push(node->ch[1]);
		if (node->ch[0]->size > position) {
			node->ch[0] = _suberase(node->ch[0], position);
			if (balanced) {
				return _eraseadjust(node, 0);
			}
			return recalc(node);
		}
		if (node->ch[0]->size < position) {
			node->ch[1] = _suberase(node->ch[1], position - node->ch[0]->size - 1);
			if (balanced) {
				return _eraseadjust(node, 1);
			}
			return recalc(node);
		}
		if (node->ch[0] != &nodes[0]) {
			if (node->ch[1] != &nodes[0]) {
				node->ch[1] = _suberase(node->ch[1], 0);
				node->value = backup->value;
				if (balanced) {
					return _eraseadjust(node, 1);
				}
				return recalc(node);
			}
			node->ch[0]->par = node->par;
			node->ch[0]->color = 1;
			++node->ch[0]->height;
			balanced = 0;
			return node->ch[0];
		}
		backup = node;
		if (node->ch[1] != &nodes[0]) {
			node->ch[1]->par = node->par;
			node->ch[1]->color = 1;
			++node->ch[1]->height;
			balanced = 0;
			return node->ch[1];
		}
		balanced = node->color;
		return &nodes[0];
	}
	Node *_eraseadjust(Node *node, uint32 dir) {
		if (node->ch[dir ^ 1]->ch[0]->color&&node->ch[dir ^ 1]->ch[1]->color) {
			if (node->ch[dir ^ 1]->color) {
				node->ch[dir ^ 1]->color = 0;
				--node->ch[dir ^ 1]->height;
				balanced = node->color;
				node->height -= node->color;
				node->color = 1;
				return recalc(node);
			}
			push(node->ch[dir ^ 1]->ch[0]);
			push(node->ch[dir ^ 1]->ch[1]);
			node = rotate(node, dir);
			node->ch[dir] = _eraseadjust(node->ch[dir], dir);
			return node;
		}
		balanced = 0;
		push(node->ch[dir ^ 1]->ch[0]);
		push(node->ch[dir ^ 1]->ch[1]);
		if (node->ch[dir ^ 1]->ch[dir ^ 1]->color) {
			push(node->ch[dir ^ 1]->ch[dir]->ch[0]);
			push(node->ch[dir ^ 1]->ch[dir]->ch[1]);
			node->ch[dir ^ 1] = rotate(node->ch[dir ^ 1], dir ^ 1);
		}
		node = rotate(node, dir);
		++node->height;
		++node->ch[0]->height;
		node->ch[0]->color = 1;
		++node->ch[1]->height;
		node->ch[1]->color = 1;
		return node;
	}
	Monoid range(Node *root, uint32 begin, uint32 end) {
		Node *t = root;
		Monoid ret;
		while (1) {
			push(t);
			if (t->ch[0]->size < begin) {
				begin -= t->ch[0]->size + 1;
				end -= t->ch[0]->size + 1;
				t = t->ch[1];
				continue;
			}
			if (t->ch[0]->size < end) {
				end -= t->ch[0]->size + 1;
				ret = t->value;
				root = t->ch[0];
				t = t->ch[1];
				break;
			}
			t = t->ch[0];
		}
		while (root != &nodes[0]) {
			push(root);
			if (root->ch[0]->size < begin) {
				begin -= root->ch[0]->size + 1;
				root = root->ch[1];
				continue;
			}
			if (root->ch[1] != &nodes[0]) {
				push(root->ch[1]);
				ret = (root->value + root->ch[1]->sum) + ret;
			}
			else ret = root->value + ret;
			root = root->ch[0];
		}
		while (t != &nodes[0]) {
			push(t);
			if (t->ch[0]->size < end) {
				end -= t->ch[0]->size + 1;
				if (t->ch[0] != &nodes[0]) {
					push(t->ch[0]);
					ret = ret + (t->ch[0]->sum + t->value);
				}
				else ret = ret + t->value;
				t = t->ch[1];
				continue;
			}
			t = t->ch[0];
		}
		return ret;
	}
	void update(Node *root, uint32 begin, uint32 end, const Operand &data) {
		Node *t = root;
		push(t);
		while (1) {
			push(t->ch[0]);
			push(t->ch[1]);
			if (t->ch[0]->size < begin) {
				begin -= t->ch[0]->size + 1;
				end -= t->ch[0]->size + 1;
				t = t->ch[1];
				continue;
			}
			if (t->ch[0]->size < end) {
				end -= t->ch[0]->size + 1;
				t->value = t->value*data;
				backup = t;
				break;
			}
			t = t->ch[0];
		}
		root = t->ch[0];
		while (root != &nodes[0]) {
			backup = root;
			if (root->ch[0]->size < begin) {
				begin -= root->ch[0]->size + 1;
				push(root->ch[0]);
				push(root->ch[1]);
				root = root->ch[1];
				continue;
			}
			root->value = root->value*data;
			root->ch[1]->lazy = root->ch[1]->lazy*data;
			push(root->ch[0]);
			push(root->ch[1]);
			root = root->ch[0];
		}
		while (backup != t) {
			backup = recalc(backup)->par;
		}
		root = t->ch[1];
		while (root != &nodes[0]) {
			t = root;
			if (root->ch[0]->size < end) {
				end -= root->ch[0]->size + 1;
				root->value = root->value*data;
				root->ch[0]->lazy = root->ch[0]->lazy*data;
				push(root->ch[0]);
				push(root->ch[1]);
				root = root->ch[1];
				continue;
			}
			push(root->ch[0]);
			push(root->ch[1]);
			root = root->ch[0];
		}
		while (t != nullptr) {
			t = recalc(t)->par;
		}
		return;
	}
	Node *_submerge(Node *left, Node *right, Node *mid) {
		uint32 dir = 1;
		if (left->height < right->height) {
			dir = 0;
			std::swap(left, right);
		}
		if (right == &nodes[0]) {
			uint32 t = itr;
			itr = (mid - &nodes[0]) - 1;
			if (dir) {
				left = insert(left, mid->value, left->size);
			}
			else {
				left = insert(left, mid->value, 0);
			}
			itr = t;
			return left;
		}
		push(left);
		push(right);
		while (left->height != right->height) {
			push(left->ch[0]);
			push(left->ch[1]);
			left = left->ch[dir];
		}
		mid->ch[dir ^ 1] = left;
		mid->ch[dir] = right;
		recalc(mid)->par = left->par;
		mid->height = left->height;
		mid->color = 0;
		left->par = mid;
		right->par = mid;
		push(left->ch[0]);
		push(left->ch[1]);
		balanced = 1;
		while (mid->par != nullptr) {
			mid->par->ch[dir] = mid;
			mid = mid->par;
			if (balanced) {
				mid = _insertadjust(mid, dir);
			}
			else {
				recalc(mid);
			}
		}
		if (!mid->color) {
			++mid->height;
			mid->color = 1;
		}
		return mid;
	}
	Node *merge(Node *left, Node *right) {
		if (right == &nodes[0]) {
			return left;
		}
		right = erase(right, 0);
		return _submerge(left, right, backup);
	}
	void show(Node *node) {
		std::cout << "(";
		if (node->ch[0] != &nodes[0]) {
			show(node->ch[0]);
			std::cout << "←";
		}
		std::cout << node->size << " " << (node->color?"黒":"赤") << " " << node->height;
		if (node->ch[1] != &nodes[0]) {
			std::cout << "→";
			show(node->ch[1]);
		}
		std::cout << ")";
		return;
	}
	void check(Node *node) {
		if (node->ch[0] != &nodes[0]) {
			if (node->ch[0]->par != node)
				std::cerr << "#\n";
			check(node->ch[0]);
		}
		if (node->ch[1] != &nodes[0]) {
			if (node->ch[1]->par != node)
				std::cerr << "#\n";
			check(node->ch[1]);
		}
	}
};
struct SUB {
	int32 e;
	bool a;
	SUB() { inactive(); }
	SUB(int32 x, bool y) { e = x; a = y; }
	void inactive(void) {
		a = false;
	}
	SUB operator*(const SUB &other) {
		if (other.a) return other;
		return *this;
	}
};
struct MIN {
	int32 e;
	MIN() { set(); }
	MIN(int32 x) { e = x; }
	void set() { e = 2147483647; }
	void reverse(void) {}
	MIN operator+(const MIN &other) {
		if (e < other.e) return *this;
		return other;
	};
	MIN operator*(const SUB &other) {
		if (other.a) return MIN(other.e);
		return *this;
	}
};
int main(void) {
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);
	uint32 n, q;
	std::cin >> n >> q;
	RBTrees<MIN, SUB> T(n);
	RBnode<MIN, SUB> *r = T.nil();
	uint32 c;
	uint32 s, t;
	SUB x;
	x.a = 1;
	//*
	rep(i, 0, n) {
		RBnode<MIN, SUB> *A;
		A = T.insert(T.nil(), MIN(2147483647), 0);
		r = T.merge(A, r);
		//T.show(r);std::cout << "\n";T.check(r);
	}
	/*/
	std::queue<RBnode<MIN, SUB> *> Q;
	rep(i, 0, n) {
		Q.push(T.insert(r, MIN(2147483647), 0));
	}
	while (Q.size() != 1) {
		RBnode<MIN, SUB> *A, *B;
		A = Q.front();Q.pop();
		B = Q.front();Q.pop();
		Q.push(T.merge(A, B));
	}
	r = Q.front();Q.pop();
	//*/
	//T.show(r);std::cout << "\n";T.check(r);
	rep(i, 0, q) {
		std::cin >> c >> s >> t;
		if (c == 0) {
			std::cin >> x.e;
			T.update(r, s, t + 1, x);
			//T.show(r);std::cout << "\n";T.check(r);
		}
		else {
			std::cout << T.range(r, s, t + 1).e << "\n";
		}
	}
	return 0;
}


Measured memory_bytes: 10796