#![allow(unused_imports, dead_code, unused_macros, unused_variables, non_snake_case, unused_parens)]
use std::cmp::*;
use std::mem::swap;
use std::collections::*;

const MOD:u64 = 1_000_000_007;
const INF:i64 = 0x7fff_ffff_ffff_ffff;

macro_rules! min {($a:expr $(,)*) => {{$a}};($a:expr, $b:expr $(,)*) => {{std::cmp::min($a, $b)}};($a:expr, $($rest:expr),+ $(,)*) => {{std::cmp::min($a, min!($($rest),+))}};}
macro_rules! max {($a:expr $(,)*) => {{$a}};($a:expr, $b:expr $(,)*) => {{std::cmp::max($a, $b)}};($a:expr, $($rest:expr),+ $(,)*) => {{std::cmp::max($a, max!($($rest),+))}};}
macro_rules! mulvec {($x:expr; $s:expr) => {vec![$x; $s]};($x:expr; $s0:expr; $( $s:expr );+) => {mulvec![vec![$x; $s0]; $( $s );+ ]};}


fn solve() {
    input! {
        n: usize,
        m: usize,
        C:[usize;n],
		UV:[(usize,usize);m],
    }
	let mut ccnt = HashMap::new();
	for (i, &c) in C.iter().enumerate() {
		ccnt.entry(c).or_insert(vec![]).push(i);
	}
	let mut uf = UnionFind::new(n);
	for (u,v) in UV {
		let u = u-1;
		let v = v-1;
		if C[u] != C[v] {continue}
		uf.unite(u, v);
	}
    let mut ans = 0;
	for (_, idxs) in ccnt.iter() {
		let mut cnt = HashSet::new();
		for &i in idxs {
			cnt.insert(uf.find(i));
		}
		ans += cnt.len()-1;
	}
    println!("{}", ans);
}

fn main() {
    std::thread::Builder::new()
        .stack_size(128 * 1024 * 1024)
        .spawn(|| solve()).unwrap()
        .join().unwrap();
}

pub struct UnionFind {
	parents: Vec<i32>,
}
impl UnionFind {
	pub fn new(n: usize) -> Self {
		UnionFind {
			parents: vec![-1_i32; n],
		}
	}

	pub fn find(&mut self, x: usize) -> usize {
		if self.parents[x] < 0 {
			return x;
		}
		self.parents[x] = self.find(self.parents[x] as usize) as i32;
		self.parents[x] as usize
	}

	pub fn same(&mut self, x:usize, y:usize) -> bool {
		self.find(x) == self.find(y)
	}

	pub fn unite(&mut self, x:usize, y:usize) -> bool {
		let mut x = self.find(x) as usize;
		let mut y = self.find(y) as usize;
		if x == y {
			return false;
		}
		if self.parents[x] > self.parents[y] {
			std::mem::swap(&mut x, &mut y);
		}
		self.parents[x] += self.parents[y];
		self.parents[y] = x as i32;
		true
	}

	pub fn size(&mut self, x:usize) -> usize {
		let parent = self.find(x);
		(-self.parents[parent]) as usize
	}
}



mod _input {
    // https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
    #[macro_export]
    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_export]
    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)*}
        };
    }
    #[macro_export]
    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<_>>()
        };

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

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

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