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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

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

public class Main {
    // template start ---8<-----------8<---
	FastScanner sc = new FastScanner(System.in);
	static PrintWriter out;

	public static void main(String[] args) throws IOException {
		out = new PrintWriter(System.out);
		new Main().solve();
		out.flush();
	}
	// template end ---8<-----------8<---


	int N;
	int M;
	int[] perm;
	int[] clr;
	void solve() {

		N = sc.nextInt();
		M = sc.nextInt();
		perm = new int[10001];
		clr = new int[10001];
		for (int i=1;i<=N;i++) {
			perm[i] = sc.nextInt();
			clr[i] = i;
		}
		int x;
		int y;
		for (int i=0;i<M;i++) {
			x = sc.nextInt();
			y = sc.nextInt();
			if (fnd(x) == fnd(y)) {
				continue;
			}
			clr[clr[y]] = clr[x];
		}

		for (int i=1;i<=N;i++) {
			fnd(i);
		}
		int ans = 0;
		for (int i=1;i<=N;i++) {
			if (clr[i] == clr[perm[i]]) {
				ans++;
			}
		}
		out.println(ans);
	}

	int fnd(int x) {
		if (x != clr[x]) {
			clr[x] = fnd(clr[x]);
		}
		return clr[x];
	}

    // template start ---8<-----------8<---
	class FastScanner {
		private final InputStream in;
		private final byte[] buffer = new byte[1024];
		private int ptr = 0;
		private int buflen = 0;

		FastScanner(InputStream in) {
			this.in = in;
		}

		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 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 Random {
		private long seed;
		private final long multiplier = 0x5DEECE66DL, addend = 0xBL, mask = (1L << 48) - 1;
		int bits, val;

		Random(long seed) {
			this.seed = seed;
		}

		int nextInt(int n) {
			do {
				bits = (int) ((seed = (seed * multiplier + addend) & mask) >>> 17);
				val = bits % n;
			} while (bits - val + (n - 1) < 0);
			return val;
		}

		double nextDouble() {
			return nextInt(10000000) / 10000000.0;
		}
	}

	final double TEMP = 10;
	static final long TL = 5850;
	static boolean submit = true;
    // template end ---8<-----------8<---

}