ARC097D

// Problem: D - Equals
// Contest: AtCoder - AtCoder Regular Contest 097
// URL: https://atcoder.jp/contests/arc097/tasks/arc097_b
// Memory Limit: 1024 MB
// Time Limit: 2000 ms
//
// Powered by CP Editor (https://cpeditor.org)

#include <assert.h>
#include <bits/stdc++.h>
#include <atcoder/dsu>
using namespace std;
#define dbg(...) logger(#__VA_ARGS__, __VA_ARGS__)
template <typename... Args> void logger(string vars, Args &&... values)
{
    cerr << vars << " = ";
    string delim = "";
    (..., (cerr << delim << values, delim = ", "));
    cerr << endl;
}

template <class T> inline auto vv(int m) { return vector<vector<T>>(m, vector<T>(m)); }
template <class T> inline auto vv(int m, int n) { return vector<vector<T>>(m, vector<T>(n)); }
template <class T, T init> inline auto vv(int m) { return vector<vector<T>>(m, vector<T>(m, init)); }
template <class T, T init> inline auto vv(int m, int n) { return vector<vector<T>>(m, vector<T>(n, init)); }

template <class T> using mpq = priority_queue<T, vector<T>, greater<T>>;
using vi = vector<int>;
using ll = long long;
using pii = pair<int, int>;
using atcoder::dsu;

int main(int argc, char **argv)
{
    int n, m;
    cin >> n >> m;
    vi p(n);
    for (int i = 0; i < n; ++i)
        cin >> p[i];
    dsu d(n);
    int x, y;
    for (int i = 0; i < m; ++i) {
        cin >> x >> y;
        d.merge(x - 1, y - 1);
    }
    int ans = 0;
    for (const auto &g : d.groups()) {
        set<int> s(g.begin(), g.end());
        for (auto x : g) {
            if (s.count(p[x] - 1))
                ans++;
        }
    }
    cout << ans << endl;
    return 0;
};