#include <bits/stdc++.h>
#define For(i, a, b) for(int (i)=(a); (i)<(b); (i)++)
#define rFor(i, a, b) for(int (i)=(a)-1; (i)>=(b); (i)--)
#define rep(i, n) For((i), 0, (n))
#define rrep(i, n) rFor((i), (n), 0)
using namespace std;
typedef long long lint;
typedef pair<int, int> pii;
template<class T> struct LazySegTree{
    int n = 1;
    int initv;
    vector<T> node, lazy;
    vector<bool> flag;

    LazySegTree(int n_, T initv_){
        while(n < n_) n *= 2;
        initv = initv_;
        node.resize(2*n-1, initv);
        lazy.resize(2*n-1, 0);
        flag.resize(2*n-1, false);
    }

    void eval(int i, int l, int r){
        if(!flag[i]) return;
        node[i] = lazy[i];
        if(r - l > 1){
            lazy[i*2+1] = lazy[i];
            flag[i*2+1] = true;
            lazy[i*2+2] = lazy[i];
            flag[i*2+2] = true;
        }
        flag[i] = false;
        lazy[i] = 0;
    }

    void update(int a, int b, int i, T x, int l, int r){
        eval(i, l, r);
        if(r<=a || b<=l) return;
        if(a<=l && r<=b){
            lazy[i] = x;
            flag[i] = true;
            eval(i, l, r);
            return;
        }
        update(a, b, i*2+1, x, l, (l+r)/2);
        update(a, b, i*2+2, x, (l+r)/2, r);
        node[i] = min(node[i*2+1], node[i*2+2]);
    }

    T getmin(int a, int b, int i, int l, int r){
        eval(i, l, r);
        if(r<=a || b<=l) return initv;
        if(a<=l && r<=b) return node[i];
        T vl = getmin(a, b, i*2+1, l, (l+r)/2);
        T vr = getmin(a, b, i*2+2, (l+r)/2, r);
        return min(vl, vr);
    }
};

int main(){
    int n, q; cin >> n >> q;
    LazySegTree<int> lst(n, INT_MAX);
    rep(i, q){
        int c; cin >> c;
        if(c){
            int s, t; cin >> s >> t;
            cout << lst.getmin(s, t+1, 0, 0, lst.n) << endl;
        }
        else{
            int s, t, x; cin >> s >> t >> x;
            lst.update(s, t+1, 0, x, 0, lst.n);
        }
    }
}
