#include<bits/stdc++.h>
using namespace std;
const int maxn = 100005, inf = 2147483647;template<class T> void read(T &re)
{re=0;T sign=1;char tmp;while((tmp=getchar())&&(tmp<'0'||tmp>'9')) if(tmp=='-') sign=-1;re=tmp-'0';while((tmp=getchar())&&(tmp>='0'&&tmp<='9')) re=(re<<3)+(re<<1)+(tmp-'0');re*=sign;
}int n, m, root[maxn<<1], rt, a[maxn];
int tot, cnt, lson[maxn<<1], rson[maxn<<1], stak[maxn], top, s[maxn], snum;struct Splay_tree{int fa, s[2], val, siz, num;
}tr[maxn * 20];void update(int x)
{int ls = tr[x].s[0], rs = tr[x].s[1];tr[x].siz = tr[ls].siz + tr[rs].siz + tr[x].num;
}void Rotate(int x)
{int y = tr[x].fa, z = tr[y].fa, k = (tr[y].s[1] == x), w = (tr[z].s[1] == y), son = tr[x].s[k^1];tr[y].s[k] = son;tr[son].fa = y;tr[x].s[k^1] = y;tr[y].fa = x;tr[z].s[w] = x;tr[x].fa = z;update(y);update(x);
}void Splay(int x, int to, int id)
{int y, z;while(tr[x].fa != to){y = tr[x].fa;z = tr[y].fa;if(z != to)Rotate((tr[y].s[0] == x) ^ (tr[z].s[0] == y)? x: y);Rotate(x);}if(!to)root[id] = x;
}void Insert(int x, int v)
{int now = root[x], ff = 0;while(now){ff = now;tr[now].siz ++;if(tr[now].val == v)    break;now = tr[now].s[v>tr[now].val];}if(now)tr[now].num ++;else{if(snum)now = s[snum--];elsenow = ++cnt;tr[now].val = v;tr[ff].s[v>tr[ff].val] = now;tr[now].fa = ff;tr[now].num = 1;tr[now].siz = 1;tr[now].s[0] = tr[now].s[1] = 0;}Splay(now, 0, x);
}void build(int &x, int l, int r)
{x = ++tot;root[x] = ++cnt;tr[root[x]].val = -inf;tr[root[x]].siz = tr[root[x]].num = 1;tr[0].s[1] = root[x];Insert(x, inf);for(int i = l; i <= r; ++i)Insert(x, a[i]);if(l == r)    return ;int mid = (l + r)>>1;build(lson[x], l, mid);build(rson[x], mid + 1, r);
}void Extract(int x, int l, int r, int L, int R)
{if(l <= L && R <= r){stak[++top] = x;return ;}int mid = (L + R)>>1;if(l <= mid)Extract(lson[x], l, r, L, mid);if(mid < r)Extract(rson[x], l, r, mid + 1, R);
}int Queryrk(int id, int x)
{int now = root[id], ret = 0;while(now){int ls = tr[now].s[0], rs = tr[now].s[1];if(x < tr[now].val){if(ls)now = ls;elsebreak;}    else if(x == tr[now].val){ret += tr[ls].siz ;break;}else{ret += tr[ls].siz + tr[now].num;if(rs)now = rs;elsebreak;}}tr[0].s[1] = root[id];Splay(now, 0, id);return ret;
}int work1(int x)
{int ret = -top;while(top){ret += Queryrk(stak[top], x);top --;}return ret + 1;
}int check(int x)
{int ret = 0;for(int i = 1; i <= top; ++i)ret += Queryrk(stak[i], x);return ret + 1;
}int work2(int x)
{x += top;int l = 0, r = 1e8, mid, ret = 0;while(l <= r){mid = (l + r)>>1;if(check(mid) <= x)ret = mid, l = mid + 1;elser = mid - 1;}top = 0;return ret;
}int Find(int now, int x)
{while(1){int ls = tr[now].s[0], rs = tr[now].s[1];if(tr[now].val == x)    return now;if(x < tr[now].val)    now = ls;else    now = rs;}
}int Querypre(int now)
{now = tr[now].s[0];while(tr[now].s[1])    now = tr[now].s[1];return now;
}int Querynxt(int now)
{now = tr[now].s[1];while(tr[now].s[0])    now = tr[now].s[0];return now;
}void Modify(int x, int pos, int l, int r, int v)
{tr[0].s[1] = root[x];int y = Find(root[x], a[pos]);Splay(y, 0, x);int pre = Querypre(root[x]);int nxt = Querynxt(root[x]);Splay(pre, 0, x);Splay(nxt, pre, x);if(tr[y].num > 1){tr[y].num --;tr[y].siz --;}else{s[++snum] = y;tr[nxt].s[0] = 0;}update(nxt);update(pre);Insert(x, v);if(l == r){a[pos] = v;return ;}int mid = (l + r)>>1;if(pos <= mid)Modify(lson[x], pos, l, mid, v);elseModify(rson[x], pos, mid + 1, r, v);
}int Findmx(int now, int x)
{int ret = 0;while(now){int ls = tr[now].s[0], rs = tr[now].s[1];if(tr[now].val == x)return now;if(tr[now].val > x){ret = now;now = ls;}elsenow = rs;}return ret;
}int Findmn(int now, int x)
{int ret = 0;while(now){int ls = tr[now].s[0], rs = tr[now].s[1];if(tr[now].val == x)return now;if(tr[now].val < x){ret = now;now = rs;}elsenow = ls;}return ret;
}int work3(int x)
{int ret = -inf;while(top){tr[0].s[1] = root[stak[top]];int now = Findmx(root[stak[top]], x);Splay(now, 0, stak[top]);int pre = Querypre(root[stak[top]]);ret = max(ret, tr[pre].val);top--;}return ret;
}int work4(int x)
{int ret = inf;while(top){tr[0].s[1] = root[stak[top]];int now = Findmn(root[stak[top]], x);Splay(now, 0, stak[top]);int nxt = Querynxt(root[stak[top]]);ret = min(ret, tr[nxt].val);top--;}return ret;
}int main()
{read(n);read(m);for(int i = 1; i <= n; ++i)read(a[i]);build(rt, 1, n);for(int i = 1; i <= m; ++i){int opt, l, r, k, pos;read(opt);if(opt == 1){read(l);read(r);read(k);Extract(rt, l, r, 1, n);printf("%d\n", work1(k));}else if(opt == 2){read(l);read(r);read(k);Extract(rt, l, r, 1, n);printf("%d\n", work2(k));}else if(opt == 3){read(pos);read(k);Modify(rt, pos, 1, n, k);}else if(opt == 4){read(l);read(r);read(k);Extract(rt, l, r, 1, n);printf("%d\n", work3(k));}else{read(l);read(r);read(k);Extract(rt, l, r, 1, n);printf("%d\n", work4(k));}}return 0;
}