#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i, n) for(int i=0; i<n; i++)
#define REPR(i, n) for(int i=n-1; i>=0; i--)
#define FOR(i, m, n) for(int i=m; i<n; i++)
#define ALL(v) v.begin(), v.end()
#define SIZE(x) ll(x.size()) 
using P = pair<int, int>;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = 2e9;
const ll LINF = (1LL<<60);

template <class S, S (*op)(S, S), S (*e)()> struct segtree {
  public:
    segtree() : segtree(0) {}
    segtree(int n) : segtree(vector<S>(n, e())) {}
    segtree(const vector<S>& v) : _n(int(v.size())) {
      log = 0;
      while ((1U << log) < (unsigned int)(_n)) log++;
      size = 1 << log;
      d = vector<S>(2 * size, e());
      for (int i = 0; i < _n; i++) d[size + i] = v[i];
      for (int i = size - 1; i >= 1; i--) update(i);
    }

    void set(int p, S x) {
      assert(0 <= p && p < _n);
      p += size;
      d[p] = x;
      for (int i = 1; i <= log; i++) update(p >> i);
    }

    S get(int p) {
      assert(0 <= p && p < _n);
      return d[p + size];
    }

    S prod(int l, int r) {
      assert(0 <= l && l <= r && r <= _n);
      S sml = e(), smr = e();
      l += size;
      r += size;

      while (l < r) {
        if (l & 1) sml = op(sml, d[l++]);
        if (r & 1) smr = op(d[--r], smr);
        l >>= 1;
        r >>= 1;
      }
      return op(sml, smr);
    }

    S all_prod() { return d[1]; }

    template <bool (*f)(S)> int max_right(int l) {
      return max_right(l, [](S x) { return f(x); });
    }
    template <class F> int max_right(int l, F f) {
      assert(0 <= l && l <= _n);
      assert(f(e()));
      if (l == _n) return _n;
      l += size;
      S sm = e();
      do {
        while (l % 2 == 0) l >>= 1;
        if (!f(op(sm, d[l]))) {
          while (l < size) {
            l = (2 * l);
            if (f(op(sm, d[l]))) {
              sm = op(sm, d[l]);
              l++;
            }
          }
          return l - size;
        }
        sm = op(sm, d[l]);
        l++;
      } while ((l & -l) != l);
      return _n;
    }

    template <bool (*f)(S)> int min_left(int r) {
      return min_left(r, [](S x) { return f(x); });
    }
    template <class F> int min_left(int r, F f) {
      assert(0 <= r && r <= _n);
      assert(f(e()));
      if (r == 0) return 0;
      r += size;
      S sm = e();
      do {
        r--;
        while (r > 1 && (r % 2)) r >>= 1;
        if (!f(op(d[r], sm))) {
          while (r < size) {
            r = (2 * r + 1);
            if (f(op(d[r], sm))) {
              sm = op(d[r], sm);
              r--;
            }
          }
          return r + 1 - size;
        }
        sm = op(d[r], sm);
      } while ((r & -r) != r);
      return 0;
    }

  private:
    int _n, size, log;
    vector<S> d;

    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
};

int op(int a, int b){
  return max(a,b);
}

int e(){
  return -1;
}

int target;

bool f(int v){
  return v < target;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n,q; cin >> n >> q;
  vector<int> a(n);
  REP(i,n) cin >> a[i];

  segtree<int, op, e> seg(a);

  while(q--){
    int t; cin >> t;
    if(t==1){
      int x,v; cin >> x >> v;
      x--;
      seg.set(x, v);
    }else if(t==2){
      int l,r; cin >> l >> r;
      l--;
      cout << seg.prod(l,r) << '\n';
    }else{
      int x; cin >> x >> target;
      x--;
      cout << seg.max_right<f>(x) + 1 << '\n';
    }
  }

  return 0;
}


Measured memory_bytes: 6084