#include <bits/stdc++.h>
#define For(i, a, b) for(int (i)=(int)(a); (i)<(int)(b); ++(i))
#define rFor(i, a, b) for(int (i)=(int)(a)-1; (i)>=(int)(b); --(i))
#define rep(i, n) For((i), 0, (n))
#define rrep(i, n) rFor((i), (n), 0)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef unsigned long long ulint;
typedef pair<int, int> pii;
typedef pair<lint, lint> pll;
template<class T> bool chmax(T &a, const T &b){if(a<b){a=b; return true;} return false;}
template<class T> bool chmin(T &a, const T &b){if(a>b){a=b; return true;} return false;}
template<class T> T div_floor(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>=0 ? a/b : (a+1)/b-1;
}
template<class T> T div_ceil(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>0 ? (a-1)/b+1 : a/b;
}

constexpr lint mod = 1e9+7;
constexpr lint INF = mod * mod;
constexpr int MAX = 200010;

struct SegTree_beats{
    const lint b_INF = 1LL << 60;
    int sz;
    vector<lint> MAX_val, sMAX_val, MAX_cnt;
    vector<lint> min_val, smin_val, min_cnt;
    vector<lint> len, sum, ladd, lval;

    void init_node(int i, lint x){
        MAX_val[i] = min_val[i] = sum[i] = x;
        sMAX_val[i] = -b_INF; smin_val[i] = b_INF;
        MAX_cnt[i] = min_cnt[i] = 1;
    }

    void init_empty_node(int i){
        MAX_val[i] = sMAX_val[i] = -b_INF;
        min_val[i] = smin_val[i] = b_INF;
        MAX_cnt[i] = min_cnt[i] = 0;
    }

    void update_node_max(int i, lint x){
        sum[i] += (x - MAX_val[i]) * MAX_cnt[i];
        if(MAX_val[i] == min_val[i]) MAX_val[i] = min_val[i] = x;
        else if(MAX_val[i] == smin_val[i]) MAX_val[i] = smin_val[i] = x;
        else MAX_val[i] = x;
        if(lval[i] != b_INF && lval[i] < x) lval[i] = x;
    }

    void update_node_min(int i, lint x){
        sum[i] += (x - min_val[i]) * min_cnt[i];
        if(min_val[i] == MAX_val[i]) min_val[i] = MAX_val[i] = x;
        else if(MAX_val[i] == smin_val[i]) min_val[i] = sMAX_val[i] = x;
        else min_val[i] = x;
        if(lval[i] != b_INF && x < lval[i]) lval[i] = x;
    }

    void update_node_add(int i, lint x, int l, int r){
        MAX_val[i] += x;
        if(sMAX_val[i] != -b_INF) sMAX_val[i] += x;
        min_val[i] += x;
        if(smin_val[i] != b_INF) smin_val[i] += x;
        sum[i] += x * (r - l);
        if(lval[i] != b_INF) lval[i] += x;
        else ladd[i] += x;
    }

    void update_node_set(int i, lint x, int l, int r){
        MAX_val[i] = min_val[i] = x;
        sMAX_val[i] = -b_INF; smin_val[i] = b_INF;
        MAX_cnt[i] = min_cnt[i] = r - l;
        lval[i] = x; ladd[i] = 0;
    }

    void push(int i, int l, int r){
        if(lval[i] != b_INF){
            update_node_set(i*2+1, lval[i], l, (l+r)/2);
            update_node_set(i*2+2, lval[i], (l+r)/2, r);
            lval[i] = b_INF;
            return;
        }
        if(ladd[i] != 0){
            update_node_add(i*2+1, ladd[i], l, (l+r)/2);
            update_node_add(i*2+2, ladd[i], (l+r)/2, r);
            ladd[i] = 0;
        }
        if(MAX_val[i] < MAX_val[i*2+1]) update_node_max(i*2+1, MAX_val[i]);
        if(MAX_val[i] < MAX_val[i*2+2]) update_node_max(i*2+2, MAX_val[i]);
        if(min_val[i] > min_val[i*2+1]) update_node_min(i*2+1, min_val[i]);
        if(min_val[i] > min_val[i*2+2]) update_node_min(i*2+2, min_val[i]);
    }

    void pull(int i){
        int s = i*2+1, t = i*2+2;
        sum[i] = sum[s] + sum[t];

        
        if(MAX_val[s] > MAX_val[t]){
            MAX_val[i] = MAX_val[s];
            MAX_cnt[i] = MAX_cnt[s];
            sMAX_val[i] = max(sMAX_val[s], MAX_val[t]);
        }
        else if(MAX_val[s] < MAX_val[t]){
            MAX_val[i] = MAX_val[t];
            MAX_cnt[i] = MAX_cnt[t];
            sMAX_val[i] = max(MAX_val[s], sMAX_val[t]);
        }
        else{
            MAX_val[i] = MAX_val[s];
            MAX_cnt[i] = MAX_cnt[s] + MAX_cnt[t];
            sMAX_val[i] = max(sMAX_val[s], sMAX_val[t]);
        }

        if(min_val[s] < min_val[t]){
            min_val[i] = min_val[s];
            min_cnt[i] = min_cnt[s];
            smin_val[i] = min(smin_val[s], min_val[t]);
        }
        else if(min_val[s] > min_val[t]){
            min_val[i] = min_val[t];
            min_cnt[i] = min_cnt[t];
            smin_val[i] = min(min_val[s], smin_val[t]);
        }
        else{
            min_val[i] = min_val[s];
            min_cnt[i] = min_cnt[s] + min_cnt[t];
            smin_val[i] = min(smin_val[s], smin_val[t]);
        }
    }

    SegTree_beats(int sz_, lint x){
        sz = 1;
        while(sz < sz_) sz *= 2;
        MAX_val.resize(sz*2-1); sMAX_val.resize(sz*2-1); MAX_cnt.resize(sz*2-1);
        min_val.resize(sz*2-1); smin_val.resize(sz*2-1); min_cnt.resize(sz*2-1);
        sum.resize(sz*2-1); ladd.resize(sz*2-1, 0); lval.resize(sz*2-1, b_INF);
        
        rep(i, sz_) init_node(i+sz-1, x);
        For(i, sz_, sz) init_empty_node(i+sz-1);
        rrep(i, sz-1) pull(i);
    }

    SegTree_beats(int sz_, vector<lint> &a){
        sz = 1;
        while(sz < sz_) sz *= 2;
        MAX_val.resize(sz*2-1); sMAX_val.resize(sz*2-1); MAX_cnt.resize(sz*2-1);
        min_val.resize(sz*2-1); smin_val.resize(sz*2-1); min_cnt.resize(sz*2-1);
        sum.resize(sz*2-1); ladd.resize(sz*2-1, 0); lval.resize(sz*2-1, b_INF);
        
        rep(i, a.size()) init_node(i+sz-1, a[i]);
        For(i, a.size(), sz) init_empty_node(i+sz-1);
        rrep(i, sz-1) pull(i);
    }

    void update_min(int a, int b, lint x, int i=0, int l=0, int r=-1){
        if(r < 0) r = sz;
        if(r<=a || b<=l || MAX_val[i] <= x) return;
        else if(a<=l && r<=b && sMAX_val[i] < x){
            update_node_max(i, x);
        }
        else{
            push(i, l, r);
            update_min(a, b, x, i*2+1, l, (l+r)/2);
            update_min(a, b, x, i*2+2, (l+r)/2, r);
            pull(i);
        }
    }

    void update_max(int a, int b, lint x, int i=0, int l=0, int r=-1){
        if(r < 0) r = sz;
        if(r<=a || b<=l || min_val[i] >= x) return;
        else if(a<=l && r<=b && smin_val[i] > x){
            update_node_min(i, x);
        }
        else{
            push(i, l, r);
            update_max(a, b, x, i*2+1, l, (l+r)/2);
            update_max(a, b, x, i*2+2, (l+r)/2, r);
            pull(i);
        }
    }

    void update_add(int a, int b, lint x, int i=0, int l=0, int r=-1){
        if(r < 0) r = sz;
        if(r<=a || b<=l) return;
        else if(a<=l && r<=b) update_node_add(i, x, l, r);
        else{
            push(i, l, r);
            update_add(a, b, x, i*2+1, l, (l+r)/2);
            update_add(a, b, x, i*2+2, (l+r)/2, r);
            pull(i);
        }
    }

    void update_set(int a, int b, lint x, int i=0, int l=0, int r=-1){
        if(r < 0) r = sz;
        if(r<=a || b<=l) return;
        else if(a<=l && r<=b) update_node_set(i, x, l, r);
        else{
            push(i, l, r);
            update_set(a, b, x, i*2+1, l, (l+r)/2);
            update_set(a, b, x, i*2+2, (l+r)/2, r);
            pull(i);
        }
    }

    lint get_max(int a, int b, int i=0, int l=0, int r=-1){
        if(r < 0) r = sz;
        if(r<=a || b<=l) return -b_INF;
        else if(a<=l && r<=b) return MAX_val[i];
        else{
            push(i, l, r);
            lint vl = get_max(a, b, i*2+1, l, (l+r)/2);
            lint vr = get_max(a, b, i*2+2, (l+r)/2, r);
            return max(vl, vr);
        }
    }

    lint get_min(int a, int b, int i=0, int l=0, int r=-1){
        if(r < 0) r = sz;
        if(r<=a || b<=l) return b_INF;
        else if(a<=l && r<=b) return min_val[i];
        else{
            push(i, l, r);
            lint vl = get_min(a, b, i*2+1, l, (l+r)/2);
            lint vr = get_min(a, b, i*2+2, (l+r)/2, r);
            return min(vl, vr);
        }
    }

    lint get_sum(int a, int b, int i=0, int l=0, int r=-1){
        if(r < 0) r = sz;
        if(r<=a || b<=l) return 0;
        else if(a<=l && r<=b) return sum[i];
        else{
            push(i, l, r);
            lint vl = get_sum(a, b, i*2+1, l, (l+r)/2);
            lint vr = get_sum(a, b, i*2+2, (l+r)/2, r);
            return vl + vr;
        }
    }
};

int main(){
    int n, q;
    scanf("%d%d", &n, &q);
    SegTree_beats st(n, 2147483647);
    rep(_, q){
        int c, s, t; lint x;
        scanf("%d%d%d", &c, &s, &t);
        if(c == 0){
            scanf("%lld", &x);
            st.update_set(s, t+1, x);
        }
        else printf("%lld\n", st.get_min(s, t+1));
    }
}


Measured memory_bytes: 21308