Problem:
Score : 400 points

Problem Statement

We have a permutation of the integers from 1 through N, p_1, p_2, .., p_N.
We also have M pairs of two integers between 1 and N (inclusive), represented as (x_1,y_1), (x_2,y_2), .., (x_M,y_M).
AtCoDeer the deer is going to perform the following operation on p as many times as desired so that the number of i (1 ≤ i ≤ N) such that p_i = i is maximized:

Choose j such that 1 ≤ j ≤ M, and swap p_{x_j} and p_{y_j}.

Find the maximum possible number of i such that p_i = i after operations.

Constraints

2 ≤ N ≤ 10^5

1 ≤ M ≤ 10^5

p is a permutation of integers from 1 through N.

1 ≤ x_j,y_j ≤ N

x_j ≠ y_j

If i ≠ j, \{x_i,y_i\} ≠ \{x_j,y_j\}.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
p_1 p_2 .. p_N
x_1 y_1
x_2 y_2
:
x_M y_M

Output

Print the maximum possible number of i such that p_i = i after operations.

Sample Input 1

5 2
5 3 1 4 2
1 3
5 4

Sample Output 1

2

If we perform the operation by choosing j=1, p becomes 1 3 5 4 2, which is optimal, so the answer is 2.

Sample Input 2

3 2
3 2 1
1 2
2 3

Sample Output 2

3

If we perform the operation by, for example, choosing j=1, j=2, j=1 in this order, p becomes 1 2 3, which is obviously optimal.
Note that we may choose the same j any number of times.

Sample Input 3

10 8
5 3 6 8 7 10 9 1 2 4
3 1
4 1
5 9
2 5
6 5
3 5
8 9
7 9

Sample Output 3

8

Sample Input 4

5 1
1 2 3 4 5
1 5

Sample Output 4

5

We do not have to perform the operation.

Solution in Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;

import javax.swing.plaf.metal.MetalBorders.InternalFrameBorder;

import java.util.*;

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }

    private int readByte() {
        if (hasNextByte())
            return buffer[ptr++];
        else
            return -1;
    }

    private static boolean isPrintableChar(int c) {
        return 33 <= c && c <= 126;
    }

    public boolean hasNext() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr]))
            ptr++;
        return hasNextByte();
    }

    public String next() {
        if (!hasNext())
            throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext())
            throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }

    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
            throw new NumberFormatException();
        return (int) nl;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }
}


class UnionFind {
    int count;
    private int[] parent;
    private int[] size;

    UnionFind(int n) {
        count = n;
        parent = new int[n];
        size = new int[n];
        for (int i = 0; i < n; i++) {
            parent[i] = i;
            size[i] = 1;
        }
    }

    int root(int n) {
        while (n != parent[n]) {
            n = parent[n] = parent[parent[n]];
        }
        return n;
    }

    void unite(int x, int y) {
        x = root(x);
        y = root(y);
        if (x != y) {
            parent[x] = y;
            size[y] += size[x];
            count--;
        }
    }

    boolean same(int x, int y) {
        return root(x) == root(y);
    }

    int getSize(int n) {
        return size[root(n)];
    }
}

public class Main {
    static int MOD = 1000000007;

    public static class Mas {
        int x;
        int y;
        int step;

        Mas(int x, int y, int step) {
            this.x = x;
            this.y = y;
            this.step = step;
        }
    }

    static long pow(long l, long i) {
        if (i == 0)
            return 1;
        else {
            if (i % 2 == 0) {
                long val = pow(l, i / 2);
                return val * val % 2019;
            } else {
                return pow(l, i - 1) * l % 2019;
            }
        }
    }

    private static final int[] vX = { 1, 0, 0, -1 };
    private static final int[] vY = { 0, 1, -1, 0 };

    static class Edge {
        int idx;
        int node;

        public Edge(int n, int i) {
            this.idx = i;
            this.node = n;
        }
    }

    static int stocks = 0;

    static long maxProfit(int k, int[] prices) {
        int n = prices.length - 1;
        if (n <= 1)
            return 0;
        long maxPro = 1000;
        int idx = 0;
        for (int i = 0; i < n; i++) {
            if (prices[i + 1] < prices[i]) {
                maxPro += (maxPro / prices[idx]) * (prices[i] - prices[idx]);
                idx = i + 1;

                // System.out.println("sotck"+stocks);
            }
            // System.out.println("money "+maxPro+"stock "+stocks+"price"+prices[i]);
            // System.out.println(maxPro);

        }
        return Math.max(maxPro, 1000);
    }

    

    public static void main(String[] args) throws IOException {
        FastScanner fs = new FastScanner();

        int n = fs.nextInt();
        int m = fs.nextInt();
        UnionFind uf = new UnionFind(n+1);
        int[] a = new int[n+1];
        for (int i = 1; i <= n; i++) {
            a[i] = fs.nextInt();
        }
        for (int i = 0; i < m; i++) {
            int v = fs.nextInt();
            int v2 = fs.nextInt();
            uf.unite(v, v2);
        }

        int ans=0;
        for (int i = 1; i <= n; i++) {
           
            if (a[i] == i) {
                ans++;
            } else {
                if (uf.same(a[i], i)) {
                    ans++;
                }
            }
        }

        System.out.println(ans);
    }
}