#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ull long long
#define PII  pair<int ,int>
const int INF = 0x3f3f3f3f3f3f3f;
const int mod = 1e9 + 7;
const int N = 1e6 + 5;
int fp(int a, int x, int mod) {
    int ans = 1;
    while (x) {
        if (x & 1)ans *= a;
        ans %= mod;
        a *= a;
        a %= mod;
        x >>= 1;
    }
    return ans;
}
bool check1(int n) {
    for (int i = 2; i <= n / 2; i++) {
        if (n % i == 0)return 0;
    }
    return 1;
}
struct tree {
    int sum, pre, suf;
    int tag = -1;
};
tree tr[4 * N];
int ls(int p) { return p << 1; }
int rs(int p) { return (p << 1) + 1; }
int history[N], tot = 0;
void add_tag(int p, int d, int pl, int pr) {
    tr[p].tag += d;
    tr[p].sum += d * (pr - pl + 1);
}
void push_down(int p, int len) {
    if (tr[p].tag != -1) {
        tr[ls(p)].tag = tr[rs(p)].tag = tr[p].tag;
        tr[ls(p)].pre = tr[ls(p)].sum = (tr[p].tag == 0) ? 0 : (len - (len >> 1));
        tr[rs(p)].pre = tr[rs(p)].sum = (tr[p].tag == 0) ? 0 : (len >> 1);
        tr[p].tag = -1;
    }
}
void push_up(int p, int len) {
    tr[p].pre = tr[ls(p)].pre;
    tr[p].suf = tr[rs(p)].suf;
    if (tr[ls(p)].pre == (len - (len >> 1))) {
        tr[p].pre = tr[ls(p)].pre + tr[rs(p)].pre;
    }
    if (tr[rs(p)].suf == (len >> 1)) {
        tr[p].suf = tr[rs(p)].suf + tr[ls(p)].suf;
    }
}
void build(int pl, int pr, int p) {
    tr[p].tag = -1;
    if (pl == pr) {
        tr[p].sum = tr[p].pre = tr[p].suf = 1;
        return;
    }
    int mid = (pl + pr) >> 1;
    build(pl, mid, ls(p));
    build(mid + 1, pr, rs(p));
    push_up(p, pr - pl + 1);
}

void update(int L, int R, int c, int p, int pl, int pr) {
    if (L <= pl && R >= pr) {
        tr[p].pre = tr[p].suf = tr[p].sum = (c == 0) ? 0 : pr - pl + 1;
        tr[p].tag = c;
        return;
    }
    int mid = (pl + pr) >> 1;
    if (L <= mid)update(L, R, c, ls(p), pl, mid);
    if (R > mid)update(L, R, c, rs(p), mid + 1, pr);
    //else update(x, c, rs(p), mid + 1, pr);
    push_up(p, pr - pl + 1);
}

int query(int len, int p, int pl, int pr) {
    if (pl == pr)return pl;
    int mid = (pl + pr) >> 1;
    if (len <= tr[ls(p)].sum) {
        if (len <= tr[p].pre)return pl;
        else return query(len, ls(p), pl, mid);
    }
    else if (len <= tr[rs(p)].pre + tr[ls(p)].suf) {
        return mid - tr[ls(p)].suf + 1;
    }
    else if (len <= tr[rs(p)].sum) {
        if (len <= tr[rs(p)].pre)return pl;
        else return query(len, rs(p), mid + 1, pr);
    }

}


//const int N = 1e6;
struct edge {
    int u, v;
};
struct node {
    int w;
    int id;
    bool operator<(const node a)const {
        return w < a.w;
    }
};
int degree[N];
node a[N];
//vector<edge>e[N];
priority_queue<node>q;
priority_queue<node>e[N];
node st[N];
int top = 0;
int cnt = 0;
bool vis[N];

void solve() {
    int n, m;
    cin >> n >> m;
    int k = n;
    int cnt = n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i].w;
        vis[i] = 1;
        a[i].id = i;
        q.push(a[i]);
    }
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
       /* e[u].push_back({ u,v });
        e[v].push_back({ v,u });*/
        e[u].push(a[v]);
        e[v].push(a[u]);
        degree[v]++;
        degree[u]++;
    }
    while (cnt >1) {
        while ((vis[q.top().id]==0||degree[q.top().id] < 2)&&!q.empty()) {
            q.pop();
            if (q.empty())break;
        }
        if (q.empty())break;
        node u = q.top();
        q.pop();
        node q1 = e[u.id].top();
        e[u.id].pop();
        while (vis[q1.id] == 0) {
            q1 = e[u.id].top();
            e[u.id].pop();
        }
        node q2 = e[u.id].top();
        e[u.id].pop();
        while (vis[q2.id] == 0) {
            q2 = e[u.id].top();
            e[u.id].pop();
        }
        cnt -= 2;
        k++;
        a[k].w = max(min(q1.w, q2.w), u.w);
        a[k].id = k;
        map<int, bool>vv;
        vis[q1.id] = 0;
        vis[q2.id] = 0;
        vis[u.id] = 0;
        while (!e[q1.id].empty()) {
            node p = e[q1.id].top();
            e[q1.id].pop();
            if (vis[p.id] == 0)continue;
            degree[k]++;
            e[p.id].push(a[k]);
            e[k].push(a[p.id]);
            vv[p.id]=1;
        }
        while (!e[q2.id].empty()) {
            node p = e[q2.id].top();
            e[q2.id].pop();
            if (vis[p.id] == 0)continue;
            degree[p.id]--;
            if (vv.count(p.id) != 0)continue;
            degree[k]++;
            e[p.id].push(a[k]);
            e[k].push(a[p.id]);
        }
        q.push(a[k]);
        vis[k] = 1;
        
    }
    cout << a[k].w << endl;
}

signed main() {
   ios::sync_with_stdio(0);
   cin.tie(0), cout.tie(0);
    int t = 1;
    //cin >> t;
    while (t--) {
        solve();
    }
}
/*
 7 7
  1 1 2 3 1 2 1
  1 2
  2 3
  1 3
  2 4
  2 5
  5 6
  5 7
*/