#include <iostream>
#include <cassert>
#include <vector>
using namespace std;
typedef long long ll;

template <typename T = int>
struct edge
{
    int from, to;
    T cost;
    int id;

    operator int() const
    {
        return to;
    }
};

template <typename T = int>
struct graph
{
    int n, m;
    std::vector<std::vector<edge<T>>> g;

    graph() {}

    graph(int n) : n(n), m(0)
    {
        g.resize(n);
    }

    void add_directed_edge(int from, int to, T cost = 1)
    {
        assert(0 <= from && from < n);
        assert(0 <= to && to < n);
        g[from].push_back((edge<T>){from, to, cost, m++});
    }

    void add_undirected_edge(int from, int to, T cost = 1)
    {
        assert(0 <= from && from < n);
        assert(0 <= to && to < n);
        g[from].push_back((edge<T>){from, to, cost, m});
        g[to].push_back((edge<T>){to, from, cost, m++});
    }

    int size()
    {
        return n;
    }

    int edge_size()
    {
        return m;
    }

    inline const std::vector<edge<T>> &operator[](const int &u) const
    {
        return g[u];
    }

    inline std::vector<edge<T>> &operator[](const int &u)
    {
        return g[u];
    }
};

int main()
{
    int n, m;
    cin >> n >> m;
    ll h[100005];
    for (int u = 0; u < n; u++)
    {
        cin >> h[u];
    }
    graph<ll> g(n * 2), r(n * 2);
    for (int u = 0; u < n; u++)
    {
        g.add_directed_edge(u * 2, u * 2 + 1, 0);
        r.add_directed_edge(u * 2 + 1, u * 2, 0);
    }
    for (int i = 0; i < m; i++)
    {
        int x, y;
        cin >> x >> y;
        x--;
        y--;
        if (x > y)
        {
            swap(x, y);
        }
        if (h[x] < h[y])
        {
            g.add_directed_edge(x * 2, y * 2 + 1, h[y] - h[x]);
            r.add_directed_edge(y * 2, x * 2 + 1, 0);
        }
        else
        {
            g.add_directed_edge(x * 2 + 1, y * 2, 0);
            r.add_directed_edge(y * 2 + 1, x * 2, h[x] - h[y]);
        }
    }
    ll d0[200005], d1[200005];
    for (int u = 0; u < n * 2; u++)
    {
        d0[u] = d1[u] = -1;
    }
    d0[0] = 0;
    for (int u = 0; u < n * 2; u++)
    {
        if (d0[u] == -1)
        {
            continue;
        }
        for (edge<ll> e : g[u])
        {
            d0[e.to] = max(d0[e.to], d0[u] + e.cost);
        }
    }
    cout << d0[n * 2 - 1] << endl;
    d1[n * 2 - 1] = 0;
    for (int u = n * 2 - 1; u >= 0; u--)
    {
        if (d1[u] == -1)
        {
            continue;
        }
        for (edge<ll> e : r[u])
        {
            d1[e.to] = max(d1[e.to], d1[u] + e.cost);
        }
    }
    cout << d1[0] << endl;
}