#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")


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

namespace brute {
vector<int> run() {
  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

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];
    }
    
    const auto ans = brute::run();
    for (int q = 0; q < Q; ++q) {
      printf("%d\n", ans[q] + 1);
    }
  }
  return 0;
}