#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int segsize = 18;

int SegTree[1<<segsize],Lazy[1<<segsize];
bool Flag[1<<segsize];
void denpa(int k,int l,int r)
{
	if(Flag[k])
	{
		SegTree[k]=Lazy[k];
		if(Lazy[k]!=INT_MAX)
		if(r-l>1)
		{
			Lazy[2*k] = Lazy[2*k+1] = Lazy[k];
			Flag[k*2] = Flag[k*2+1]=true;
		}
		Flag[k] = false;
	}
}

void update(int a,int b,ll x,int k=1,int l=0,int r =-1)
{
	if(r<0)r=(1<<(segsize-1));
	//cout<<a<<' '<<b<<' '<<x<<' '<<k<<' '<<l<<' '<<r<<endl;
	denpa(k,l,r);
	if(b<=l||r<=a)return;
	if(a<=l&&r<=b)
	{
		Lazy[k] = x;
		Flag[k] = true;
		denpa(k,l,r);
	}
	else
	{
		update(a,b,x,k*2,l,(l+r)/2);
		update(a,b,x,k*2+1,(l+r)/2,r);
		SegTree[k] = min(SegTree[k*2],SegTree[k*2+1]);
	}
}

ll getmin(int a,int b,int k=1,int l=0,int r=-1)
{
	if(r<0)r = 1<<(segsize-1);
	denpa(k,l,r);
	if(b<=l||r<=a)return INT_MAX;
	if(a<=l&&r<=b)return SegTree[k];
	ll vl = getmin(a,b,k*2,l,(l+r)/2);
	ll vr = getmin(a,b,2*k+1,(l+r)/2,r);
	return min(vl,vr);
}

int main()
{
	for(int i = 0;i<(1<<segsize);i++)
	{
		SegTree[i]=INT_MAX;
		Lazy[i] = INT_MAX;
	}
	int n,q;
	cin >> n >> q;
	for(int i = 0;i<q;i++)
	{
		int op;
		cin >> op;
		if(op)
		{
			int a,b;
			cin >> a >> b;
			b++;
			cout<<getmin(a,b)<<endl;
		}
		else
		{
			int a,b,x;
			cin >> a >> b >> x;
			b++;
			update(a,b,x);
		}
		//for (int i = 0; i < (1<<segsize); i++){cout<<SegTree[i]<<' '<<Lazy[i]<<endl;}cout<<endl;
		
		
	}
}
