#![allow(non_snake_case, unused)]
use std::cmp::*;
use std::collections::*;
use std::f64::consts::*;

macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, [ $t:tt ]) => {
        {
            let len = read_value!($next, usize);
            (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
        }
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, bytes) => {
        read_value!($next, String).into_bytes()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

struct UnionFind {
    par: Vec<usize>,
    rank: Vec<usize>,
    size: Vec<usize>,
}

impl UnionFind {
    fn new(n: usize) -> UnionFind {
        let mut v = vec![0; n];
        for i in 0..n {
            v[i] = i;
        }
        UnionFind {
            par: v,
            rank: vec![0; n],
            size: vec![1; n],
        }
    }

    fn find(&mut self, x: usize) -> usize {
        if self.par[x] == x {
            x
        } else {
            let par = self.par[x];
            self.par[x] = self.find(par);
            self.par[x]
        }
    }

    fn unite(&mut self, a: usize, b: usize) {
        let apar = self.find(a);
        let bpar = self.find(b);
        let asize = self.size[apar];
        let bsize = self.size[bpar];
        if self.rank[apar] > self.rank[bpar] {
            self.par[bpar] = apar;
            self.size[a] += self.size[b];
        } else {
            self.par[apar] = bpar;
            self.size[b] += self.size[a];
            if self.rank[apar] == self.rank[bpar] {
                self.rank[bpar] += 1;
            }
        }
    }
}

fn main() {
    input! {
        n: usize, m: usize,
        p: [usize1; n],
        xy: [(usize1, usize1); m],
    }

    let mut cnt = 0;
    let mut uf = UnionFind::new(n);
    let mut sizes = vec![1; n];

    for (x, y) in xy {
        if uf.find(x) != uf.find(y) {
            uf.unite(x, y);
        }
    }

    let mut cnt = 0;

    for i in 0..n {
        if uf.find(i) == uf.find(p[i]) {
            cnt += 1;
        }
    }

    println!("{}", cnt);
}


Measured memory_bytes: 10492