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

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;
typedef pair<int, int> pii;
typedef pair<ll, ld> pld;
typedef pair<pii, int> ppiii;
typedef pair<pii, ll> ppiil;
typedef pair<pll, ll> pplll;
typedef pair<pli, int> pplii;
typedef vector<vector<ll>> vvl;
typedef vector<vector<int>> vvi;
typedef vector<vector<pll>> vvpll;
#define rep(i, a, b) for (ll i=(a); i<(b); i++)
#define rrep(i, a, b) for (ll i=(a); i>(b); i--)
#define pb push_back
#define tostr to_string
#define mkp make_pair
const ll INF = 1e18;
const ll MOD = 1e9 + 7;

void print(ld out) { cout << fixed << setprecision(12) << out << '\n'; }
template<typename T> void print(T out) { cout << out << '\n'; }
template<typename T1, typename T2> void print(pair<T1, T2> out) { cout << out.first << ' ' << out.second << '\n'; }
template<typename T> void print(vector<T> A) { rep(i, 0, A.size()) { cout << A[i]; cout << (i == A.size()-1 ? '\n' : ' '); } }
template<typename T> void print(set<T> S) { vector<T> A(S.begin(), S.end()); print(A); }

template<typename T> inline bool chmax(T &x, T y) { return (y > x) ? x = y, true : false; }
template<typename T> inline bool chmin(T &x, T y) { return (y < x) ? x = y, true : false; }

ll sum(vector<ll> A) { ll res = 0; for (ll a: A) res += a; return res; }
ll max(vector<ll> A) { ll res = -INF; for (ll a: A) chmax(res, a); return res; }
ll min(vector<ll> A) { ll res = INF; for (ll a: A) chmin(res, a); return res; }

ll toint(string s) { ll res = 0; for (char c : s) { res *= 10; res += (c - '0'); } return res; }
int toint(char c) { return c - '0'; }
char tochar(int i) { return '0' + i; }

inline ll pow(int x, ll n) { ll res = 1; rep(_, 0, n) res *= x; return res; }
inline ll pow(ll x, ll n, int mod) { ll res = 1; while (n > 0) { if (n & 1) { res = (res * x) % mod; } x = (x * x) % mod; n >>= 1; } return res; }

inline ll floor(ll a, ll b) { if (a < 0) { return (a-b+1) / b; } else { return a / b; } }
inline ll ceil(ll a, ll b) { if (a >= 0) { return (a+b-1) / b; } else { return a / b; } }

int popcount(ll S) { return __builtin_popcountll(S); }
ll gcd(ll a, ll b) { return __gcd(a, b); }

template <typename T,typename E>
struct SegmentTree{
    typedef function<T(T,T)> F;
    typedef function<T(T,E)> G;
    typedef function<E(E,E)> H;
    typedef function<E(E,int)> P;
    int n;
    F f;
    G g;
    H h;
    P p;
    T d1;
    E d0;
    vector<T> dat;
    vector<E> laz;
    SegmentTree(int n_,F f,G g,H h,T d1,E d0,
            vector<T> v=vector<T>(),P p=[](E a,int b){return a;}):
        f(f),g(g),h(h),d1(d1),d0(d0),p(p){
        init(n_);
        if(n_==(int)v.size()) build(n_,v);
    }
    void init(int n_){
        n=1;
        while(n<n_) n*=2;
        dat.clear();
        dat.resize(2*n-1,d1);
        laz.clear();
        laz.resize(2*n-1,d0);
    }
    void build(int n_, vector<T> v){
        for(int i=0;i<n_;i++) dat[i+n-1]=v[i];
        for(int i=n-2;i>=0;i--)
        dat[i]=f(dat[i*2+1],dat[i*2+2]);
    }
    inline void eval(int len,int k){
        if(laz[k]==d0) return;
        if(k*2+1<n*2-1){
        laz[k*2+1]=h(laz[k*2+1],laz[k]);
        laz[k*2+2]=h(laz[k*2+2],laz[k]);
        }
        dat[k]=g(dat[k],p(laz[k],len));
        laz[k]=d0;
    }
    T update(int a,int b,E x,int k,int l,int r){
        eval(r-l,k);
        if(r<=a||b<=l) return dat[k];
        if(a<=l&&r<=b){
        laz[k]=h(laz[k],x);
        return g(dat[k],p(laz[k],r-l));
        }
        return dat[k]=f(update(a,b,x,k*2+1,l,(l+r)/2),
                update(a,b,x,k*2+2,(l+r)/2,r));
    }
    T update(int a,int b,E x){
        return update(a,b,x,0,0,n);
    }
    T query(int a,int b,int k,int l,int r){
        eval(r-l,k);
        if(r<=a||b<=l) return d1;
        if(a<=l&&r<=b) return dat[k];
        T vl=query(a,b,k*2+1,l,(l+r)/2);
        T vr=query(a,b,k*2+2,(l+r)/2,r);
        return f(vl,vr);
    }
    T query(int a,int b){
        return query(a,b,0,0,n);
    }
};

ll N, Q;
// 区間更新・区間最小取得
auto f = [](ll a, ll b) -> ll { return min(a, b); };
auto g = [](ll a, ll b) -> ll { (void)a; return b; };
auto h = [](ll a, ll b) -> ll { (void)a; return b; };
auto p = [](ll a, ll b) -> ll { return a; };

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

    cin >> N >> Q;
    SegmentTree<ll, ll> seg(N, f, g, h, INT_MAX, -1, vector<ll>(N, INT_MAX), p);

    ll op, s, t, x;
    rep(i, 0, Q) {
        cin >> op;
        if (op == 0) {
            cin >> s >> t >> x;
            seg.update(s, t+1, x);
        } else {
            cin >> s >> t;
            print(seg.query(s, t+1));
        }
    }
    return 0;
}



Measured memory_bytes: 8632