#include <bits/stdc++.h>
using namespace std;

int id = INT_MAX;
int id2 = -1;
int merge(int l, int r) {
	return min(l, r);
}
int merge2(int l, int r) {
	return r == id2 ? l : r;
}

template <typename T>
struct node {
	T val, all, lazy;
	node<T> *ch[2];
	unsigned int pri;
	int size;
	node(T v, unsigned int p, node<T>* l = nullptr, node<T>* r = nullptr) : val(v), all(v), lazy(id2), pri(p), size(1) {
		ch[0] = l; ch[1] = r;
	}
};

unsigned xor128() {
	static unsigned x = 123456789, y = 362436069, z = 521288629, w = 88675123;
	unsigned t = x ^ (x << 11);
	x = y; y = z; z = w;
	return w = w ^ (w >> 19) ^ (t ^ (t >> 8));
}

template <typename T>
int count(node<T> *t) { return t == nullptr ? 0 : t->size; }
template <typename T>
T que(node<T> *t) { return t == nullptr ? id : merge2(t->all, t->lazy); }
template <typename T>
node<T> *update(node<T> *t) {
	t->size = count(t->ch[0]) + count(t->ch[1]) + 1;
	t->all = merge(que(t->ch[0]), merge(t->val, que(t->ch[1])));
	return t;
}
template <typename T>
node<T> *push(node<T> *t) {
	if (t == nullptr || t->lazy == id2) return t;
	if (t->ch[0] != nullptr) {
		t->ch[0]->lazy = merge2(t->ch[0]->lazy, t->lazy);
	}
	if (t->ch[1] != nullptr) {
		t->ch[1]->lazy = merge2(t->ch[1]->lazy, t->lazy);
	}
	t->val = merge2(t->val, t->lazy);
	t->all = merge(que(t->ch[0]), merge(t->val, que(t->ch[1])));
	t->lazy = id2;
	return t;
}
template <typename T>
node<T> *rotate(node<T> *t, int b) {
	node<T> *s = t->ch[1 - b];
	t = push(t);
	s = push(s);
	t->ch[1 - b] = s->ch[b];
	s->ch[b] = t;
	update(t); update(s);
	return s;
}
template <typename T>
node<T> *insert(node<T> *t, int k, T v, unsigned int pri) {
	if (t == nullptr) return new node<T>(v, pri);
	t = push(t);
	int c = count(t->ch[0]), b = (k > c);
	t->ch[b] = insert(t->ch[b], k - (b ? (c + 1) : 0), v, pri);
	update(t);
	if (t->pri > t->ch[b]->pri) t = rotate(t, 1 - b);
	return t;
}
template <typename T>
node<T> *erase(node<T> *t) {
	if (t == nullptr) return nullptr;
	if (t->ch[0] == nullptr && t->ch[1] == nullptr) {
		delete t;
		return nullptr;
	}
	t = push(t);
	int b = (t->ch[0] != nullptr && t->ch[1] != nullptr) ? (t->ch[0]->pri > t->ch[1]->pri) : (t->ch[0] != nullptr);
	t = rotate(t, b);
	t->ch[b] = erase(t->ch[b]);
	update(t);
	return t;
}
template <typename T>
node<T> *erase(node<T> *t, int k) {
	if (t == nullptr) return nullptr;
	t = push(t);
	int c = count(t->ch[0]);
	if (k < c) {
		t->ch[0] = erase(t->ch[0], k);
		update(t);
	}
	else if (k > c) {
		t->ch[1] = erase(t->ch[1], k - (c + 1));
		update(t);
	}
	else {
		t = erase(t);
	}
	return t;
}
template <typename T>
node<T> *merge(node<T> *l, node<T> *r) {
	node<T> *p = new node<T>(0, 0);
	p->ch[0] = l, p->ch[1] = r;
	p = erase(p);
	return p;
}
template <typename T>
pair<node<T>*, node<T>*> split(node<T> *t, int k) {
	if (t == nullptr) return make_pair(nullptr, nullptr);
	node<T> *p = insert(t, k, 0, 0);
	auto res = make_pair(p->ch[0], p->ch[1]);
	delete p;
	return res;
}
template <typename T>
T find(node<T> *t, int l, int r) {
	if (t == nullptr) return id;
	if (r < 0 || l >= count(t)) return id;
	t = push(t);
	if (l <= 0 && r >= t->size) return t->all;
	int c = count(t->ch[0]);
	return merge(t->ch[0] == nullptr ? id : find(t->ch[0], l, r), merge(l <= c && c < r ? t->val : id, t->ch[1] == nullptr ? id : find(t->ch[1], l - (c + 1), r - (c + 1))));
}
template <typename T>
node<T> *find(node<T> *t, int k) {
	if (t == nullptr) return t;
	int c = count(t->ch[0]);
	return k < c ? find(t->ch[0], k) : k == c ? t : find(t->ch[1], k - (c + 1));
}
template <typename T>
int cnt(node<T> *t, T v) {
	if (t == nullptr) return 0;
	t = push(t);
	if (t->val < v) return count(t->ch[0]) + 1 + cnt(t->ch[1], v);
	if (t->val == v) return count(t->ch[0]);
	return cnt(t->ch[0], v);
}
template <typename T>
node<T> *update(node<T> *t, int l, int r, T v) {
	auto t1 = split(t, l);
	auto t2 = split(t1.second, r - l);
	t2.first->lazy = merge2(t2.first->lazy, v);
	return merge(t1.first, merge(t2.first, t2.second));
}

template <typename T>
void print(node<T> *t) {
	if (t == nullptr) return;
	print(t->ch[0]);
	printf(" %d", t->val);
	print(t->ch[1]);
}
template <typename T>
node<T> *shift(node<T> *t, int l, int r) {
	pair<node<T>*, node<T>*> s1 = split(t, l), s2 = split(s1.second, r - l), s3 = split(s2.second, 1);
	return merge(s1.first, merge(s3.first, merge(s2.first, s3.second)));
}
template <typename T>
void change(node<T> *t, int k, T v) {
	if (t == nullptr) return;
	int c = count(t->ch[0]);
	if (k < c) {
		change(t->ch[0], k, v);
		update(t);
	}
	else if (k > c) {
		change(t->ch[1], k - (c + 1), v);
		update(t);
	}
	else {
		t->val = v;
		update(t);
	}
}

int main()
{
	cin.sync_with_stdio(false);
	int n, q, type, s, t, x;
	cin >> n >> q;
	node<int> *root = nullptr;
	for (int i = 0; i < n; i++) {
		root = insert(root, i, id, xor128());
	}
	while (q--) {
		cin >> type;
		if (type == 0) {
			cin >> s >> t >> x;
			root = update(root, s, t + 1, x);
		}
		else {
			cin >> s >> t;
			printf("%d\n", find(root, s, t + 1));
		}
	}
	return 0;
}

Measured memory_bytes: 7924