const int N = 400005;
const int LG = 21;
const long long MOD = 1e9 + 7;
const long long INF = 1e9;

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <cmath>
#include <time.h>
#include <unordered_set>
#include <bitset>
#include <deque>

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<ll> vi;

#define forn(i, n) for (int (i) = 0; (i) != (n); (i)++)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define popcount(x) __builtin_popcount(x)
#define popcountll(x) __builtin_popcountll(x)
#define fi first
#define se second
#define re return
#define uniq(x) sort(all(x)); (x).resize(unique(all(x)) - (x).begin())

#ifdef LOCAL
#define dbg(x) cerr << __LINE__ << " " << #x << " " << x << endl
#define ln cerr << __LINE__ << endl
#else
#define dbg(x) void(0)
#define ln void(0)
#endif // LOCAL

int cx[4] = {-1, 0, 1, 0};
int cy[4] = {0, -1, 0, 1};

ll inq(ll x, ll y)
{
    if (!y) re 1 % MOD;
    ll l = inq(x, y / 2);
    if (y % 2) re l * l % MOD * x % MOD;
    re l * l % MOD;
}

ll rev(ll x)
{
    return inq(x, MOD - 2);
}

bool __precomputed_combinatorics = 0;
vector<ll> __fact, __ufact, __rev;

void __precompute_combinatorics()
{
    __precomputed_combinatorics = 1;
    __fact.resize(N);
    __ufact.resize(N);
    __rev.resize(N);
    __rev[1] = 1;
    for (int i = 2; i < N; i++) __rev[i] = MOD - __rev[MOD % i] * (MOD / i) % MOD;
    __fact[0] = 1, __ufact[0] = 1;
    for (int i = 1; i < N; i++) __fact[i] = __fact[i - 1] * i % MOD, __ufact[i] = __ufact[i - 1] * __rev[i] % MOD;
}

ll fact(int x)
{
    if (!__precomputed_combinatorics) __precompute_combinatorics();
    return __fact[x];
}

ll cnk(int n, int k)
{
    if (!__precomputed_combinatorics) __precompute_combinatorics();
    return __fact[n] * __ufact[n - k] % MOD * __ufact[k] % MOD;
}

void __fast_IO()
{
    #ifdef ONLINE_JUDGE
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        cout.tie(0);
    #endif // ONLINE_JUDGE
}

//##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**
//##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**##**

int n, m;
vector<int> graph[N];
vector<int> tree[N];
ll a[N], b[N];

bool comp(int i, int j)
{
    return a[i] - b[i] < a[j] - b[j];
}

int top[N], root[N], sz[N];

int Root(int x)
{
    if (x == root[x]) re x;
    re Root(root[x]);
}

pair<ll, ll> dfs(int v)
{
    if (tree[v].size() == 0) return {max(a[v], b[v]), b[v]};
    vector<pll> cp;
    for (auto u : tree[v])
    {
        cp.push_back(dfs(u));
    }
    sort(all(cp));
    ll pay = b[v];
    for (auto e : cp) pay += e.second;
    sort(all(cp), [&](pll a, pll b){
        return a.first - a.second < b.first - b.second;
    });
    ll min_cost_in = 1e18;
    for (int i = 0; i < cp.size(); i++)
    {
        swap(cp[0], cp[i]);
        ll cost_in = max(a[v], cp[0].first + b[v]);
        for (int i = 1; i < cp.size(); i++)
        {
            cost_in = max(cost_in + cp[i].second, cp[i].first);
        }
        min_cost_in = min(min_cost_in, cost_in);
        swap(cp[0], cp[i]);
        //next_permutation(all(cp));
    }
    return {min_cost_in, pay};
}

signed main()
{
    __fast_IO();
    cin >> n >> m;
    for (int i = 0; i < n; i++)
    {
        cin >> a[i] >> b[i];
    }
    for (int i = 0; i < m; i++)
    {
        int a, b;
        cin >> a >> b;
        a--, b--;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    vector<int> vertices(n), allowed(n);
    for (int i = 0; i < n; i++) vertices[i] = i, root[i] = i, sz[i] = 1, top[i] = i;
    sort(all(vertices), comp);
    for (int i = 0; i < vertices.size(); i++)
    {
        int v = vertices[i];
        for (auto u : graph[v])
        {
            if (!allowed[u]) continue;
            int x = Root(v), y = Root(u);
            if (x == y) continue;
            tree[v].push_back(top[y]);
            if (sz[x] > sz[y])
            {
                swap(x, y);
            }
            sz[y] += sz[x];
            root[x] = y;
            top[y] = v;
        }
        allowed[v] = 1;
    }
    int root = vertices.back();
    cout << dfs(root).first;
}

/* Note:
Check constants at the beginning of the code.
N is set to 4e5 but be careful in problems with large constant factor.
Check corner cases.
No def int long long for now.
*/


Measured memory_bytes: 44028