#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < int(n); i++)
#define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define reps(i, n) for (int i = 1; i <= int(n); i++)
#define rreps(i, n) for (int i = int(n); i >= 1; i--)
#define repc(i, n) for (int i = 0; i <= int(n); i++)
#define rrepc(i, n) for (int i = int(n); i >= 0; i--)
#define repi(i, a, b) for (int i = int(a); i < int(b); i++)
#define repic(i, a, b) for (int i = int(a); i <= int(b); i++)
#define each(x, y) for (auto &x : y)
#define all(a) (a).begin(), (a).end()
#define bit(b) (1ll << (b))

using namespace std;

using i32 = int;
using i64 = long long;
using f80 = long double;
using vi32 = vector<i32>;
using vi64 = vector<i64>;
using vf80 = vector<f80>;
using vstr = vector<string>;

inline void yes() { cout << "Yes" << '\n'; exit(0); }
inline void no() { cout << "No" << '\n'; exit(0); }
inline i64 gcd(i64 a, i64 b) { if (min(a, b) == 0) return max(a, b); if (a % b == 0) return b; return gcd(b, a % b); }
inline i64 lcm(i64 a, i64 b) { return a / gcd(a, b) * b; }
void solve(); int main() { ios::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(16); solve(); return 0; }
template <typename T> class pqasc : public priority_queue<T, vector<T>, greater<T>> {};
template <typename T> class pqdesc : public priority_queue<T, vector<T>, less<T>> {};
template <typename T> inline void amax(T &x, T y) { if (x < y) x = y; }
template <typename T> inline void amin(T &x, T y) { if (x > y) x = y; }
template <typename T> inline T power(T x, i64 n, T e = 1) { T r = e; while (n > 0) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; }
template <typename T> istream& operator>>(istream &is, vector<T> &v) { each(x, v) is >> x; return is; }
template <typename T> ostream& operator<<(ostream &os, vector<T> &v) { rep(i, v.size()) { if (i) os << ' '; os << v[i]; } return os; }
template <typename T, typename S> istream& operator>>(istream &is, pair<T, S> &p) { is >> p.first >> p.second; return is; }
template <typename T, typename S> ostream& operator<<(ostream &os, pair<T, S> &p) { os << p.first << ' ' << p.second; return os; }

template <typename T, typename S>
struct LazySegmentTree {
  using F = function<T(T, T)>;
  using G = function<T(T, S)>;
  using H = function<S(S, S)>;

  vector<T> v;
  vector<S> z;
  F f;
  G g;
  H h;
  T e;
  S d;
  int n;

  LazySegmentTree(int size, F f, G g, H h, T e, S d) : f(f), g(g), h(h), e(e), d(d) {
    n = 1;
    while (n < size) n <<= 1;
    v.resize(n * 2, e);
    z.resize(n * 2, d);
  }
  
  void set(int k, T x) {
    v[k + n] = x;
  }

  void build() {
    rrep(i, n) v[i] = f(v[i * 2 + 0], v[i * 2 + 1]);
  }

  void propagate(int k) {
    v[k] = g(v[k], z[k]);
    if (k < n) {
      z[k * 2 + 0] = h(z[k * 2 + 0], z[k]);
      z[k * 2 + 1] = h(z[k * 2 + 0], z[k]);
    }
    z[k] = d;
  }

  void update(int a, int b, S x, int k = 1, int l = 0, int r = -1) {
    if (r == -1) r = n;
    propagate(k);
    if (b <= l || r <= a) return;
    if (a <= l && r <= b) { z[k] = x; propagate(k); return; }
    update(a, b, x, k * 2 + 0, l, (l + r) / 2);
    update(a, b, x, k * 2 + 1, (l + r) / 2, r);
    v[k] = f(v[k * 2 + 0], v[k * 2 + 1]);
  }

  T query(int a, int b, int k = 1, int l = 0, int r = -1) {
    if (r == -1) r = n;
    propagate(k);
    if (b <= l || r <= a) return e;
    if (a <= l && r <= b) return v[k];
    T ret = e;
    ret = f(ret, query(a, b, k * 2 + 0, l, (l + r) / 2));
    ret = f(ret, query(a, b, k * 2 + 1, (l + r) / 2, r));
    return ret;
  }
};

void solve() {
  const int INF = bit(31) - 1;
  int n, q; cin >> n >> q;
  auto lst = LazySegmentTree<int, int>(n,
    [&](int a, int b) { return min(a, b); },
    [&](int a, int b) { return b == INF ? a : b; },
    [&](int a, int b) { return b == INF ? a : b; }, INF, INF);
  while (q--) {
    int c; cin >> c;
    if (c == 0) {
      int s, t, x; cin >> s >> t >> x;
      lst.update(s, t + 1, x);
    } else {
      int s, t; cin >> s >> t;
      cout << lst.query(s, t + 1) << '\n';
    }
  }
}



Measured memory_bytes: 4948