G open 60

/*
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┓┏┓┏┓┃＼○／
┛┗┛┗┛┃ / /
┓┏┓┏┓┃ノ
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      MIPTCLASSICMIPTCLASSICMIPTCLASSICMIPTCLASSICMIPTCLASSICMIPTCLASSIC
*/

// #define pragma

#ifdef pragma
#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#pragma GCC diagnostic ignored "-Wunused-result"
#endif // pragma

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ll long long
#define all(x) begin(x), end(x)
#define pb push_back
#define x first
#define y second
#define int long long
#define zero(two) memset(two, 0, sizeof(two))

using namespace std;
using namespace __gnu_pbds;


typedef vector<int> vi;
typedef vector<bool> vb;
typedef pair<int, int> pii;
typedef long double ld;
typedef vector<vi> matrix;
template<typename T>
using kawaii_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ld PI = atan2(0, -1);

void seriy() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cout << fixed << setprecision(10);
    #if 1
        freopen("input", "r", stdin);
        freopen("output", "w", stdout);
    #endif
}

const int INF = 1e9 + 7;

vi a, dp;
int ans = 0, cur = 0;

matrix g2, res, res2;
map<int, int> mp;
vb used2;


void dfs3(int u, int cnt) {
    used2[u] = 1;
    mp[u] = cnt + 1;
    res[cnt].pb(a[u]);
    res2[cnt].pb(u);
    for(auto v : g2[u]) {
        if(!used2[v]) {
            dfs3(v, cnt);
        }
    }
}

signed main() {
    seriy();
    int n, m;
    cin >> n >> m;
    a.resize(n);
    dp.resize(n + 1, INF);
    dp[0] = 0;
    g2.resize(n);
    used2.resize(n);
    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }
    for(int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        u--;
        v--;
        g2[u].pb(v);
        g2[v].pb(u);
    }
    int cnt = 0;
    for(int i = 0; i < n; i++) {
        if(!used2[i]) {
            res.pb({});
            res2.pb({});
            dfs3(i, cnt);
            cnt++;
        }
    }
    for(int i = 0; i < cnt; i++) {
        sort(all(res[i]), greater<int>());
    }
    vi st(n + 1, -1);
    dp[0] = 0;
    int ress = 0;
    for(int i = 0; i < n; i++) {
        int cur = mp[i] - 1;
        int mx = 0;
        int h;
        for(int j = 0; j < res[cur].size(); j++) {
            int val = res[cur][j];
            int pos = upper_bound(all(dp), val) - dp.begin();
            if(dp[pos - 1] < val && val < dp[pos]) {
                ress = max(ress, pos);
                dp[pos] = val;
                st[pos] = cur;
            }
        }
    }
    cout << ress;
}