#include <bits/stdc++.h>
#include <bits/extc++.h>
using i64 = long long;

struct Dsu
{
    int n;
    std::vector<int> f, sz;

    Dsu() {}
    Dsu(int _n) : n(_n)
    {
        f.resize(n);
        std::iota(f.begin(), f.end(), 0);
        sz.assign(n, 1);
    }
    int leader(int x)
    {
        if (f[x] == x)
            return x;
        return f[x] = leader(f[x]);
    }
    void merge(int u, int v)
    {
        u = leader(u), v = leader(v);
        if (u == v)
            return;
        if (sz[u] < sz[v])
        {
            std::swap(u, v);
        }
        f[v] = u;
        sz[u] += sz[v];
    }
    bool same(int u, int v)
    {
        return leader(u) == leader(v);
    }
    int size(int x)
    {
        return sz[leader(x)];
    }
};

void solve()
{
    int n, m;
    std::cin >> n >> m;
    std::vector<int> color(n);
    int ans = 0;
    for (auto &i : color)
    {
        std::cin >> i;
        i--;
    }

    std::vector<std::vector<int>> adj(n);
    for (int i = 0; i < m; i++)
    {
        int u, v;
        std::cin >> u >> v;
        --u, --v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    Dsu dsu(n);

    for (int i = 0; i < n; i++)
    {
        if (adj[i].empty())
            continue;
        for (const auto &j : adj[i])
        {
            if (color[i] == color[j])
            {
                dsu.merge(i, j);
            }
        }
    }

    std::vector<std::vector<int>> id(n);
    for (int i = 0; i < n; i++)
    {
        id[color[i]].push_back(i);
    }

    for (const auto &v : id)
    {
        if (v.size() <= 1)
        {
            continue;
        }
        int x = v.front();
        for (size_t i = 1; i < v.size(); i++)
        {
            int y = v[i];
            if (!dsu.same(x, y))
            {
                ans++;
                dsu.merge(x, y);
            }
        }
    }
    std::cout << ans << '\n';
}
int main()
{
    std::cin.tie(nullptr)->sync_with_stdio(false);
    solve();
    return 0;
}