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

#define rep(i,j,n) for(int i=(j);i<(n);i++)
#define erep(i,j,n) for(int i=(j);i<=(n);i++)
#define all(i) i.begin(),i.end()
#define rall(i) i.rbegin(),i.rend()
#define INF 1e9
const int mod = 1e9+7;

typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<vi> vvi;
typedef pair<int, int> pi;
typedef long long i64;

template <class Monoid, class T = Monoid> struct LazySegmentTree {
  using F = function<Monoid(Monoid, Monoid)>;

  int n;
  vector<T> node, lazy;
  vector<bool> lazyFlag; // 区間更新

  const F f;
  const Monoid M1;

  LazySegmentTree(int sz, const F f, const Monoid M1) : f(f), M1(M1) {
    n = 1;
    while(n < sz) n *= 2;
    node.resize(2 * n - 1, M1);
    lazy.resize(2 * n - 1, 0);
    lazyFlag.resize(2 * n - 1, false);
  }

  void eval(int k, int l, int r) {
    if(lazy[k] = 0) return;

    node[k] += lazy[k];
    if(r - l > 1) {
      lazy[2 * k + 1] += lazy[k] / 2;
      lazy[2 * k + 2] += lazy[k] / 2;
    }
    lazy[k] = 0;
  }

  void lazyEvaluate(int k, int l, int r) {
    if(!lazyFlag[k]) return;

    node[k] = lazy[k];
    if(r - l > 1) {
      lazy[k * 2 + 1] = lazy[k * 2 + 2] = lazy[k];
      lazyFlag[k * 2 + 1] = lazyFlag[k * 2 + 2] = true;
    }
    lazyFlag[k] = false;
  }

  void update(int a, int b, T x, int k = 0, int l = 0, int r = -1) {
    if(r < 0) r = n;

    // eval(k, l, r);
    lazyEvaluate(k, l, r);

    if(b <= l || r <= a) return;

    if(a <= l && r <= b) {
      lazy[k] = x;
      lazyFlag[k] = true;
      // eval(k, l, r);
      lazyEvaluate(k, l, r);
    }
    else {
      update(a, b, x, 2 * k + 1, l, (l + r) / 2);
      update(a, b, x, 2 * k + 2, (l + r) / 2, r);
      node[k] = f(node[k * 2 + 1], node[k * 2 + 2]);
    }
  }

  T query(int a, int b, int k = 0, int l = 0, int r = -1) {
    if(r < 0) r = n;

    // eval(k, l, r);
    lazyEvaluate(k, l, r);

    if(b <= l || r <= a) return INT_MAX;
    if(a <= l && r <= b) return node[k];
    T vl = query(a, b, 2 * k + 1, l, (l + r) / 2);
    T vr = query(a, b, 2 * k + 2, (l + r) / 2, r);
    return f(vl, vr);
  }
};

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n, q;
  cin >> n >> q;
  LazySegmentTree<int> seg(n, [](int a, int b){return min(a, b);}, INT_MAX);

  rep(i, 0, q) {
    int query, s, t;
    cin >> query >> s >> t;
    if(query) cout << seg.query(s, t + 1) << endl;
    else {
      int x;
      cin >> x;
      seg.update(s, t + 1, x);
    }
  }
}

