#line 1 "main.cpp"

/**
 * @title Template
 */

#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>

#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/chmin_chmax.cpp"

template <class T, class U>
constexpr bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) { 
    lhs = rhs; 
    return true; 
  }
  return false;
}

template <class T, class U>
constexpr bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) { 
    lhs = rhs; 
    return true; 
  }
  return false;
}

/**
 * @title Chmin/Chmax
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

#line 4 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

class range {
public:
  class iterator {
  private:
    int64_t M_position;

  public:
    constexpr iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { ++M_position; }
    constexpr bool operator != (iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };

  class reverse_iterator {
  private:
    int64_t M_position;
  
  public:
    constexpr reverse_iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { --M_position; }
    constexpr bool operator != (reverse_iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };
  
private:
  const iterator M_first, M_last;

public:
  constexpr range(int64_t first, int64_t last) noexcept: M_first(first), M_last(std::max(first, last)) { }
  constexpr iterator begin() const noexcept { return M_first; }
  constexpr iterator end() const noexcept { return M_last; }
  constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator(*M_last - 1); } 
  constexpr reverse_iterator rend() const noexcept { return reverse_iterator(*M_first - 1); } 

};

/**
 * @title Range
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

#include <type_traits>
#include <iterator>
#line 6 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

template <class T>
class rev_impl {
public:
  using iterator = typename std::decay<T>::type::reverse_iterator;

private:
  const iterator M_begin;
  const iterator M_end;

public:
  constexpr rev_impl(T &&cont) noexcept: M_begin(std::rbegin(cont)), M_end(std::rend(cont)) { }
  constexpr iterator begin() const noexcept { return M_begin; }
  constexpr iterator end() const noexcept { return M_end; }

};

template <class T>
constexpr decltype(auto) rev(T &&cont) {
  return rev_impl<T>(std::forward<T>(cont));
}

/**
 * @title Reverser
 */
#line 16 "main.cpp"

using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;

constexpr i32 inf32 = (i32(1) << 30) - 1;
constexpr i64 inf64 = (i64(1) << 62) - 1;

constexpr i32 BK = 700;

int main() {
  i32 N, Q;
  std::cin >> N >> Q;
  std::vector<i32> A(N);
  for (auto &x: A) {
    std::cin >> x;
    --x;
  }
  std::vector<i32> L(Q), R(Q);
  for (auto i: range(0, Q)) {
    std::cin >> L[i] >> R[i];
    --L[i];
  }
  std::vector<std::vector<i32>> Qs((N + BK - 1) / BK);
  for (auto i: range(0, Q)) {
    Qs[L[i] / BK].push_back(i);
  }
  std::vector<i32> ans(Q);
  for (auto k: range(0, Qs.size())) {
    auto &vec = Qs[k];
    std::sort(vec.begin(), vec.end(), [&](auto i, auto j) {
      return R[i] < R[j];
    });
    i32 l = BK * k, r = BK * k, cur = 0;
    std::vector<i32> count(N);
    for (auto i: vec) {
      while (r < R[i]) {
        if (count[A[r++]]++ == 0) {
          ++cur;
        }
      }
      while (r > R[i]) {
        if (--count[A[--r]] == 0) {
          --cur;
        }
      }
      while (l < L[i]) {
        if (--count[A[l++]] == 0) {
          --cur;
        }
      }
      while (l > L[i]) {
        if (count[A[--l]]++ == 0) {
          ++cur;
        }
      }
      ans[i] = cur;
    }
  }
  for (auto x: ans) {
    std::cout << x << '\n';
  }
  return 0;
}


Measured memory_bytes: 17000