#include<bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;
using ull = unsigned long long;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;

#define fi first
#define se second
#define pb push_back
#define pf push_front
#define mp make_pair
#define ins insert
#define btpc __builtin_popcount
#define btclz __builtin_clz

#define sz(x) (int)(x.size());
#define all(x) x.begin(), x.end()
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y)
        {
            x = y;
            return true;
        }
        return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y)
        {
            x = y;
            return true;
        }
        return false;
    }

const int MOD = 1e9 + 7; //998244353

template<class X, class Y>
	void add(X &x, const Y &y) {
		x = (x + y);
		if(x >= MOD) x -= MOD;
	}

template<class X, class Y>
	void sub(X &x, const Y &y) {
		x = (x - y);
		if(x < 0) x += MOD;
	}

/* Author : Le Ngoc Bao Anh, 11A5, LQD High School for Gifted Student*/

const ll INF = 1e9;
const int N = 3e5 + 10;

struct TrieNode {
	TrieNode* child[26];
	ll dp = 0;

	TrieNode() {
		for(int i = 0; i < 26; i++) child[i] = nullptr;
		dp = 0;
	}
};

string s[N];
int p[N];
vector<int> g[N], imp[N], nimp[N];
bool is_imp[N];
ll dp[N], f[N], b[N];

void solve() {
	int n, m; cin >> n >> m;
	for(int i = 1; i <= n; i++) {
		cin >> s[i] >> p[i];
	}

	int S = 600;
	TrieNode* root = new TrieNode();

	auto updateTrie = [&](string s, ll x) -> void {
		int n = s.size();
		TrieNode* curr = root;

		for(int i = 0; i < n; i++) {
			int p = (s[i] - 'A');
			if(curr->child[p] == nullptr) curr->child[p] = new TrieNode();
			curr = curr->child[p];
			if(i + 1 < n) maximize(curr->dp, x);
		}
	};

	auto getTrie = [&](string s) -> ll {
		int n = s.size();
		TrieNode* curr = root;

		for(int i = 0; i < n; i++) {
			int p = (s[i] - 'A');
			if(curr->child[p] == nullptr) curr->child[p] = new TrieNode();
			curr = curr->child[p];
		}

		return curr->dp;
	};

	for(int i = 1; i <= m; i++) {
		int u, v; cin >> u >> v;
		g[u].pb(v);
		g[v].pb(u);
	}

	int t = 1e5;
	for(int i = 1; i <= t; i++) {
		sort(all(g[i]));
		g[i].resize(unique(all(g[i])) - g[i].begin());
	}

	for(int i = 1; i <= t; i++) {
		is_imp[i] = (g[i].size() >= S);
	}

	for(int i = 1; i <= t; i++) {
		for(auto u : g[i]) {
			if(is_imp[u]) imp[i].pb(u);
			else nimp[i].pb(u);
		}
	}

	ll ans = 0;
	for(int i = 1; i <= n; i++) {
		dp[i] = getTrie(s[i]) + p[i];
		int u = p[i];
		maximize(dp[i], f[u] + u);
		for(auto v : imp[u]) maximize(dp[i], b[v] + p[i]);

		if(is_imp[u]) maximize(b[u], dp[i]);
		else {
			for(auto v : g[u]) maximize(f[v], dp[i]);
		}

		updateTrie(s[i], dp[i]);
		maximize(ans, dp[i]);
	}

	cout << ans;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #else
    //online
    #endif

    int tc = 1, ddd = 0;
    // cin >> tc;
    while(tc--) {
        //ddd++;
        //cout << "Case #" << ddd << ": ";
        solve();
    }
}