#include <bits/stdc++.h>
using i64 = std::int_fast64_t;
using std::cout;
using std::cerr;
using std::endl;
using std::cin;

template<typename T>
std::vector<T> make_v(size_t a){return std::vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
  return std::vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

#ifndef INCLUDED_FENWICK_TREE_HPP
#define INCLUDED_FENWICK_TREE_HPP

#include <functional>
#include <vector>

template<class CommutativeMonoid>
class fenwick_tree {
public:
	using T = typename CommutativeMonoid::value_type;
	using size_type = std::uint_fast32_t;

	using checker = std::function<bool(T)>;

	std::vector<T> data;

private:
	size_type get_lsb(size_type i) const { return i & (~i + 1); }

public:
	fenwick_tree() = default;
	fenwick_tree(const fenwick_tree &) = default;
	fenwick_tree(fenwick_tree &&) = default;

	fenwick_tree(size_type size): data(size + 1, T{}) {}

	template<class InputIt>
	fenwick_tree(InputIt first, InputIt last) : fenwick_tree(std::distance(first, last)) {
		for(int index = 0; first != last; first++, index++) add(index, *first);
	}

	fenwick_tree & operator=(const fenwick_tree &) = default;
	fenwick_tree & operator=(fenwick_tree &&) = default;

	T fold(size_type last) const {
		T acc{};
		while(last) {
			acc = CommutativeMonoid::operation(data[last], acc);

			last -= get_lsb(last);
		}

		return acc;
	}
	T fold(size_type first, size_type last) const {
		T acc{};
		while(first < last) {
			acc = CommutativeMonoid::operation(data[last], acc);

			last -= get_lsb(last);
		}

		while(last < first) {
			acc = CommutativeMonoid::operation(CommutativeMonoid::inverse(data[first]), acc);

			first -= get_lsb(first);
		}

		return acc;
	}
	void update(size_type index, const T& value) {
		for(++index; index < data.size(); index += get_lsb(index)) {
			data[index] = CommutativeMonoid::operation(data[index], value);
		}
	}
	void change(size_type index, const T& value) {
		update(index, CommutativeMonoid::operation(CommutativeMonoid::inverse((*this)[index]), value));
	}

	// min{x | f(fold(x)) = true}
	template<class F>
	size_type search(const F & f) {
		if(f(T{})) return 0;

		T acc{};
		size_type i = 0, k = data.size();
		while(k >>= 1) {
			if((i | k) < data.size() and !f(CommutativeMonoid::operation(acc, data[i | k]))) {
				acc = CommutativeMonoid::operation(acc, data[i | k]);
				i |= k;
			}
		}
		return i + 1;
	}

	T operator[](const size_type& k) const { return fold(k, k + 1); };

	bool empty() const { return size() == 0; }
	size_type size() const { return data.size() - 1; }
	void swap(fenwick_tree & r) { data.swap(r.data); }
};

template<class T>
struct monoid {
	using value_type = T;

	static value_type operation(const value_type& a, const value_type& b) { return a + b; };
	static value_type inverse(const value_type& x) { return -x; }
};

#endif

#ifndef INCLUDED_FAST_IO_HPP
#define INCLUDED_FAST_IO_HPP

#include <cstdio>
#include <cstdint>
#include <cstddef>
#include <cstring>
#include <limits>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>

namespace fast_io {
	// fast I/O by rsk0315 (update: 2020-03-02 01:10:54).
	static size_t constexpr buf_size = 1 << 17;
	static size_t constexpr margin = 1;
	static char inbuf[buf_size + margin] = {};
	static char outbuf[buf_size + margin] = {};
	static __attribute__((aligned(8))) char minibuf[32];
	static size_t constexpr int_digits = 20;	// 18446744073709551615
	static uintmax_t constexpr digit_mask = 0x3030303030303030;
	static uintmax_t constexpr first_mask = 0x00FF00FF00FF00FF;
	static uintmax_t constexpr second_mask = 0x0000FFFF0000FFFF;
	static uintmax_t constexpr third_mask = 0x00000000FFFFFFFF;
	static uintmax_t constexpr tenpow[] = {
		1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000
	};
	template <typename Tp>
	using enable_if_integral = std::enable_if<std::is_integral<Tp>::value, Tp>;

	class scanner {
		char* pos = inbuf;
		char* endpos = inbuf + buf_size;

		void M_read_from_stdin() {
			endpos = inbuf + fread(pos, 1, buf_size, stdin);
		}
		void M_reread_from_stdin() {
			ptrdiff_t len = endpos - pos;
			if (!(inbuf + len <= pos)) return;
			memcpy(inbuf, pos, len);
			char* tmp = inbuf + len;
			endpos = tmp + fread(tmp, 1, buf_size-len, stdin);
			*endpos = 0;
			pos = inbuf;
		}

	public:
		scanner() { M_read_from_stdin(); }

		template <typename Integral,
							typename enable_if_integral<Integral>::type* = nullptr>
		void scan_parallel(Integral& x) {
			// See https://qiita.com/rsk0315_h4x/items/17a9cb12e0de5fd918f4
			if (__builtin_expect(endpos <= pos + int_digits, 0))
				M_reread_from_stdin();
			bool ends = false;
			typename std::make_unsigned<Integral>::type y = 0;
			bool neg = false;
			if (std::is_signed<Integral>::value && *pos == '-') {
				neg = true;
				++pos;
			}
			do {
				memcpy(minibuf, pos, 8);
				long c = *(long*)minibuf;
				long d = (c & digit_mask) ^ digit_mask;
				int skip = 8;
				int shift = 8;
				if (d) {
					int ctz = __builtin_ctzl(d);
					if (ctz == 4) break;
					c &= (1L << (ctz-5)) - 1;
					int discarded = (68-ctz) / 8;
					shift -= discarded;
					c <<= discarded * 8;
					skip -= discarded;
					ends = true;
				}
				c |= digit_mask;
				c ^= digit_mask;
				c = ((c >> 8) + c*10) & first_mask;
				c = ((c >> 16) + c*100) & second_mask;
				c = ((c >> 32) + c*10000) & third_mask;
				y = y*tenpow[shift] + c;
				pos += skip;
			} while (!ends);
			x = (neg? -y: y);
			++pos;
		}

		template <typename Integral,
							typename enable_if_integral<Integral>::type* = nullptr>
		void scan_serial(Integral& x) {
			if (__builtin_expect(endpos <= pos + int_digits, 0))
				M_reread_from_stdin();
			bool neg = false;
			if (std::is_signed<Integral>::value && *pos == '-') {
				neg = true;
				++pos;
			}
			typename std::make_unsigned<Integral>::type y = *pos-'0';
			while (*++pos >= '0') y = 10*y + *pos-'0';
			x = (neg? -y: y);
			++pos;
		}

		template <typename Integral,
							typename enable_if_integral<Integral>::type* = nullptr>
		// Use scan_parallel(x) only when x may be too large (about 10^12).
		// Otherwise, even when x <= 10^9, scan_serial(x) may be faster.
		void scan(Integral& x) { scan_parallel(x); }

		void scan_serial(std::string& s) {
			// until first whitespace
			s = "";
			do {
				char* startpos = pos;
				while (*pos > ' ') ++pos;
				s += std::string(startpos, pos);
				if (*pos != 0) {
					++pos;	// skip the space
					break;
				}
				M_reread_from_stdin();
			} while (true);
		}

		void scan(std::string& s) { scan_serial(s); }

		void scan(char& c) {
			if (__builtin_expect(endpos <= pos + 2, 0))
				M_reread_from_stdin();
			c = *pos++;
			++pos;
		}

		template<class H, class... T>
		void scan(H& h, T&... t) {
			scan(h);
			scan(t...);
		}
	};

	class printer {
		char* pos = outbuf;

		void M_flush_stdout() {
			fwrite(outbuf, 1, pos-outbuf, stdout);
			pos = outbuf;
		}

		template <typename ... Args>
		char* format(const std::string& fmt, Args ... args ) {
			size_t len = std::snprintf( nullptr, 0, fmt.c_str(), args ... );
			char* buf = new char[len + 1];
			std::snprintf(&buf[0], len + 1, fmt.c_str(), args ... );
			return std::move(buf);
		}

	public:
		printer() = default;
		~printer() { M_flush_stdout(); }

		void print(char c) {
			if (__builtin_expect(pos + 1 >= outbuf + buf_size, 0)) M_flush_stdout();
			*pos++ = c;
		}

		template <size_t N>
		void print(char const(&s)[N]) {
			if (__builtin_expect(pos + N >= outbuf + buf_size, 0)) M_flush_stdout();
			memcpy(pos, s, N-1);
			pos += N-1;
		}

		void print(char const* s) {
			while (*s != 0) {
				*pos++ = *s++;
				if (pos == outbuf + buf_size) M_flush_stdout();
			}
		}

		void print(const std::string& s) { print(s.c_str()); }

		void print(const bool& x) {
			if(x) print(1);
			else print(0);
		}

		template <typename Integral,
							typename enable_if_integral<Integral>::type* = nullptr>
		void print(Integral x) {
			if (__builtin_expect(pos + int_digits >= outbuf + buf_size, 0))
				M_flush_stdout();
			if (x == 0) {
				*pos++ = '0';
				return;
			}
			if (x < 0) {
				*pos++ = '-';
				if (__builtin_expect(x == std::numeric_limits<Integral>::min(), 0)) {
					switch (sizeof x) {
					case 2: print("32768"); return;
					case 4: print("2147483648"); return;
					case 8: print("9223372036854775808"); return;
					}
				}
				x = -x;
			}
			char* mp = minibuf + sizeof minibuf;
			*--mp = x % 10 + '0';
			size_t len = 1;
			typename std::make_unsigned<Integral>::type y = x / 10;
			while (y > 0) {
				*--mp = y % 10 + '0';
				y /= 10;
				++len;
			}
			memcpy(pos, mp, len);
			pos += len;
		}

		template <typename Tp>
		void println(Tp const& x) { print(x), print('\n'); }

		template<class H, class... T>
		void print(const H& h, const T&... t) {
			print(h);
			print(' ');
			print(t...);
		}
		template<class T>
		void print(const std::vector<T>& t) {
			for(size_t i = 0; i < t.size(); i++) {
				print(t[i]);
				if(i + 1 != t.size()) print(' ');
			}
		}
		template<class... T>
		void println(const T&... t) { print(t...); print('\n'); }
		template<class T>
		void println(const std::vector<T>& t) { print(t); print('\n'); }
		void println() { print('\n'); }
	};
}
fast_io::scanner fin;
fast_io::printer fout;

// @docs docs/fast_io.md

#endif

int main() {
  int n, q; fin.scan(n, q);
  std::vector<int> a(n);
  for(auto& v: a) fin.scan(v);
  std::vector<int> l(q), r(q);
  for(int i = 0; i < q; i++) fin.scan(l[i], r[i]);

  std::vector<std::pair<int, int>> vec;
  for(int i = 0; i < q; i++) vec.push_back({l[i] - 1, i});
  sort(begin(vec), end(vec));

  std::vector<int> right(n, -1);
  fenwick_tree<monoid<int>> fwt(n);
  {
    std::vector<int> tmp(n + 1, -1);
    for(int i = n - 1; i >= 0; i--) {
      if(~tmp[a[i]]) right[i] = tmp[a[i]];
      tmp[a[i]] = i;

      fwt.update(i, 1);
      if(~right[i]) fwt.update(right[i], -1);
    }
  }

  std::vector<int> ans(q);
  for(int i = 0, cnt = 0; i < n; i++) {
    while(cnt < q and vec[cnt].first == i) {
      int id = vec[cnt++].second;
      ans[id] = fwt.fold(i, r[id]);
    }

    if(~right[i]) {
      fwt.update(i, -1);
      fwt.update(right[i], 1);
    }
  }

  for(auto v: ans) fout.println(v);
  return 0;
}


Measured memory_bytes: 19664