import std;

void main () {
    /*
       色ごとの全域木をつくるかんじで
       辞書型UFでずるする
     */
    int N, M; readln.read(N, M);
    int[] C = readln.split.to!(int[]);
    alias UFarr = UnionFind_Dictionary!(int);

    UFarr[int] UF;
    foreach (c; C) UF[c] = UnionFind_Any!(int);

    // 登録
    foreach (i, c; C) UF[c].addElement(cast(int) i);

    foreach (i; 0..M) {
        int u, v; readln.read(u, v);
        u--, v--;
        if (C[u] == C[v]) {
            UF[C[u]].unite(u, v);
        }
    }

    int ans = 0;
    foreach (U; UF) {
        ans += U.countGroups-1;
    }

    writeln(ans);
}

void read (T...) (string S, ref T args) {
    auto buf = S.split;
    foreach (i, ref arg; args) {
        arg = buf[i].to!(typeof(arg));
    }
}

class UnionFind_Dictionary (T) {
    private:
        T[T] parent;
        int[T] size;

    T root (T x) {
        if (x !in parent) {
            addElement(x);
            return x;
        }

        if (parent[x] == x) return x;
        return parent[x] = root(parent[x]);
    }

    bool same (T x, T y) {
        return root(x) == root(y);
    }

    void unite (T x, T y) {
        addElement(x), addElement(y);
        T larger, smaller;
        if (GroupSize(x) <= GroupSize(y)) {
            larger = root(y);
            smaller = root(x);
        } else {
            larger = root(x);
            smaller = root(y);
        }

        if (larger == smaller) return;

        parent[smaller] = larger;
        size[larger] += size[smaller];
    }

    int countGroups () {
        int res = 0;
        foreach (key, val; parent) {
            if (root(key) == key) res++;
        }
        return res;
    }

    bool addElement (T x) {
        if (x in parent) return false;
        parent[x] = x;
        size[x] = 1;
        return true;
    }

    int GroupSize (T x) {
        addElement(x);
        return size[root(x)];
    }

    T[][] enumGroups (T x) {
        T[][T] mp;
        T[][] res;
        foreach (key, val; parent) {
            mp[root(key)] ~= key;
        }

        foreach (val; mp) {
            res ~= val;
        }

        return res;
    }

    void reset () {
        parent.clear;
        size.clear;
    }
}

auto UnionFind_Any (T) () {
    return new UnionFind_Dictionary!(T)();
}

import std.range.primitives : isInputRange;
auto UnionFind_Any (T, E) (E range) if (isInputRange!(E) || is(T == S[], S) || is(T == S[n], S, size_t n)) {
    auto res = new UnionFind_Dictionary!(T)();
    foreach (elem; range) {
        res.addElement(elem);
    }

    return res;
}