#include <iostream>
#include <algorithm> // for sort, mainly
#include <vector>
#include <map>
#include <set>
#include <cmath>
#include <array>
#include <string>
#include <cstdio>
#include <iterator>
#include <unordered_set>
#include <cstdint> // for int64_t, int32_t, etc
#include <queue>
#include <stack>
#include <deque>
#include <numeric> // gcd, lcm
#include <fstream>
#include <bitset> // for bitset
#include <iomanip>
#include <cassert> // for set with custom ordering
#include <type_traits> // for set with custom ordering
#include <utility> // for swap, forward, etc
using namespace std;

#pragma GCC optimize("O2")
// #pragma GCC optimize("O1","O2","O3","Ofast","unroll-loops")
// #pragma GCC target("sse","sse2","sse3","sse4.1","sse4.2","avx","avx2","fma")

template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
void dbg_out() { cout << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
#ifdef LOCAL
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

/*

notes:

int64_t
stoi(string s) -> string to int
to_string() -> int (or else) to string

vector declaration:
vector<ll> v(n, 0)
vector<vector<ll>> v(n, vector<ll>(n, 0));

{if statement} ? {truth value} : {false value}

#ifdef LOCAL
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
#endif

std::lcm(ll a, ll b), std::gcd(int a, int b)

cout << fixed << setprecision(n);

set with custom ordering
set<ll, decltype(&cmp)> qu(cmp);

*/

typedef int64_t ll;

void solve() {

	ll n, m;
	cin >> n >> m;

	vector<ll> v(n+1, 0);
	for(ll i = 1; i <= n; i++) {
		cin >> v[i];
	}

	//cerr << "\nv=" << v;

	vector<ll> over(n+2, 0);

	for(ll qi = 0; qi < m; qi++) {
		ll a, b;
		cin >> a >> b;

		over[a]++;
		over[b+1]--;
	}

	for(ll i = 1; i <= n+1; i++) {
		over[i] += over[i-1];
	}

	//cerr << "\nover=" << over;

	vector<pair<ll,ll>> segs;
	
	ll l = -1, r = -1;
	for(ll i = 1; i <= n; i++) {

		//cerr << "\ni=" << i << "; l=" << l << "; r=" << r;

		if(over[i] > 0 && over[i-1] == 0) {
			l = i;
		}

		if(over[i] > 0 && over[i+1] == 0) {
			r = i;
			segs.push_back({l, r});
			l = -1;
			r = -1;
		}
	}

	//cerr << "\nsegs=" << segs;

	for(const auto & [from, to] : segs) {

		sort(v.begin() + from, v.begin() + to + 1);
		//cerr << "\nfrom=" << from << "; to=" << to << "\nv=" << v;
	}

	ll fin = 0;
	for(ll i = 1; i <= n; i++) {
		if(v[i] == i) {
			fin++;
		}
	}

	cout << fin;

}

int main()
{
	std::ios_base::sync_with_stdio(false);
	//cin.tie(nullptr);
	//cout.tie(nullptr);

	solve();

	return 0;
}