#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


template <class T> void bAdd(vector<T> &bit, int pos, const T &val) {
  const int bitN = bit.size();
  for (int x = pos; x < bitN; x |= x + 1) bit[x] += val;
}
template <class T> T bSum(const vector<T> &bit, int pos) {
  T ret = 0;
  for (int x = pos; x > 0; x &= x - 1) ret += bit[x - 1];
  return ret;
}
template <class T> T bSum(const vector<T> &bit, int pos0, int pos1) {
  return bSum(bit, pos1) - bSum(bit, pos0);
}

// min pos s.t. pred(sum of [0, pos))
//   assume pred(sum of [0, pos)) is non-decreasing
template <class T, class Pred>
int bBinarySearch(const vector<T> &bit, Pred pred) {
  if (pred(T(0))) return 0;
  const int bitLen = bit.size();
  int pos = 0;
  T sum = 0;
  for (int e = 31 - __builtin_clz(bitLen); e >= 0; --e) {
    const int x = (pos | 1 << e) - 1;
    if (x < bitLen && !pred(sum + bit[x])) {
      pos |= 1 << e;
      sum += bit[x];
    }
  }
  return pos + 1;
}


struct Set {
  // max{ceil(log_64(n)), 1}
  int log64N, n;
  vector<unsigned long long> a[6];
  explicit Set(int n_ = 0) : n(n_) {
    assert(n >= 0);
    int m = n ? n : 1;
    for (int d = 0; ; ++d) {
      m = (m + 63) >> 6;
      a[d].assign(m, 0);
      if (m == 1) {
        log64N = d + 1;
        break;
      }
    }
  }
  bool empty() const {
    return !a[log64N - 1][0];
  }
  bool contains(int x) const {
    return (a[0][x >> 6] >> (x & 63)) & 1;
  }
  void insert(int x) {
    for (int d = 0; d < log64N; ++d) {
      const int q = x >> 6, r = x & 63;
      a[d][q] |= 1ULL << r;
      x = q;
    }
  }
  void erase(int x) {
    for (int d = 0; d < log64N; ++d) {
      const int q = x >> 6, r = x & 63;
      if ((a[d][q] &= ~(1ULL << r))) break;
      x = q;
    }
  }
  // max s.t. <= x (or -1)
  int prev(int x) const {
    if (x > n - 1) x = n - 1;
    for (int d = 0; d <= log64N; ++d) {
      if (x < 0) break;
      const int q = x >> 6, r = x & 63;
      const unsigned long long lower = a[d][q] << (63 - r);
      if (lower) {
        x -= __builtin_clzll(lower);
        for (int e = d; --e >= 0; ) x = x << 6 | (63 - __builtin_clzll(a[e][x]));
        return x;
      }
      x = q - 1;
    }
    return -1;
  }
  // min s.t. >= x (or n)
  int next(int x) const {
    if (x < 0) x = 0;
    for (int d = 0; d < log64N; ++d) {
      const int q = x >> 6, r = x & 63;
      if (static_cast<unsigned>(q) >= a[d].size()) break;
      const unsigned long long upper = a[d][q] >> r;
      if (upper) {
        x += __builtin_ctzll(upper);
        for (int e = d; --e >= 0; ) x = x << 6 | __builtin_ctzll(a[e][x]);
        return x;
      }
      x = q + 1;
    }
    return n;
  }
};


int N, Q;
vector<int> A;
vector<int> X, K, Y;

namespace brute {
vector<int> run() {
cerr<<"[brute::run]"<<endl;
  auto as = A;
  vector<int> bs(N);
  vector<int> app(N + 1, -1);
  vector<int> ans(Q, -1);
  for (int q = 0; q < Q; ++q) {
    as[X[q]] = K[q];
    int mex = 0;
    for (int i = 0; i < N; ++i) {
      if (as[i] == -1) {
        for (; app[mex] == q; ++mex) {}
        bs[i] = mex;
      } else {
        bs[i] = as[i];
      }
      if (bs[i] >= 0) {
        app[bs[i]] = q;
      }
    }
    ans[q] = bs[Y[q]];
  }
  return ans;
}
}  // brute

namespace sub2 {
vector<int> run() {
cerr<<"[sub2::run]"<<endl;
  int I0;
  for (I0 = 0; I0 < N && A[I0] == -2; ++I0) {}
  vector<int> bit(N + 1, 0);
  for (int b = 0; b <= N; ++b) bAdd(bit, b, +1);
  auto as = A;
  vector<int> freq(N + 1, 0);
  vector<int> ans(Q, -1);
  for (int q = 0; q < Q; ++q) {
    {
      int &a = as[X[q]];
      if (a >= 0) if (!--freq[a]) bAdd(bit, a, +1);
      a = K[q];
      if (a >= 0) if (!freq[a]++) bAdd(bit, a, -1);
    }
    if (Y[q] < I0) {
      ans[q] = as[Y[q]];
    } else {
      ans[q] = bBinarySearch(bit, [&](int sum) -> bool {
        return (sum > Y[q] - I0);
      }) - 1;
    }
  }
  return ans;
}
}  // sub2

namespace sub3 {
vector<int> run() {
cerr<<"[sub3::run]"<<endl;
  vector<int> is;
  vector<int> si(N, -1);
  for (int i = 0; i < N; ++i) if (A[i] == -1) {
    si[i] = is.size();
    is.push_back(i);
  }
  const int len = min((int)is.size(), 105);
  vector<Set> exs(len, Set(N + 1));
  for (int j = 0; j < len; ++j) {
    for (int b = 0; b <= N; ++b) exs[j].insert(b);
  }
  vector<set<int>> apps(N + 1);
  for (int b = 0; b <= N; ++b) apps[b].insert(N);
  auto as = A;
  vector<int> ans(Q, -1);
  for (int q = 0; q < Q; ++q) {
    {
      int &a = as[X[q]];
      if (a >= 0) {
        apps[a].erase(X[q]);
        for (int j = 0; j < len; ++j) if (X[q] < is[j] && is[j] < *apps[a].begin()) exs[j].insert(a);
      }
      a = K[q];
      if (a >= 0) {
        for (int j = 0; j < len; ++j) if (X[q] < is[j] && is[j] < *apps[a].begin()) exs[j].erase(a);
        apps[a].insert(X[q]);
      }
    }
    {
      const int jY = si[Y[q]];
      if (~jY) {
        int b = 0;
        for (int j = 0; j < len; ++j) {
          b = exs[j].next(b);
          if (jY == j) {
            ans[q] = b;
            break;
          }
          ++b;
        }
        if (jY >= len) {
          ans[q] = b + (jY - len);
        }
      } else {
        ans[q] = as[Y[q]];
      }
    }
  }
  return ans;
}
}  // sub3

int main() {
  for (; ~scanf("%d%d", &N, &Q); ) {
    A.resize(N);
    for (int i = 0; i < N; ++i) {
      scanf("%d", &A[i]);
      --A[i];
    }
    X.resize(Q);
    K.resize(Q);
    Y.resize(Q);
    for (int q = 0; q < Q; ++q) {
      scanf("%d%d%d", &X[q], &K[q], &Y[q]);
      --X[q];
      --K[q];
      --Y[q];
    }
    
    bool spe2 = true;
    for (int i = 0; i < N - 1; ++i) spe2 = spe2 && (A[i] <= A[i + 1]);
    const bool spe3 = (*max_element(K.begin(), K.end()) < 100);
    const bool spe4 = (count(A.begin(), A.end(), -1) <= 100);
    
    vector<int> ans;
    if (spe2) {
      ans = sub2::run();
    } else if (spe3 || spe4) {
      ans = sub3::run();
    } else {
      ans = brute::run();
    }
    for (int q = 0; q < Q; ++q) {
      printf("%d\n", ans[q] + 1);
    }
  }
  return 0;
}