#include <bits/stdc++.h>
using namespace std;
const int eps = 1e-10;
const int maxn = 2000 + 10;
const int INF = 1000000000;
struct Edge {
  int from, to, cap, flow;
  int cost;
  Edge(int u, int v, int c, int f, int w)
      : from(u), to(v), cap(c), flow(f), cost(w) {}
};
struct MCMF {
  int n, m;
  vector<Edge> edges;
  vector<int> G[maxn];
  int inq[maxn];
  int d[maxn];
  int p[maxn];
  int a[maxn];
  void init(int n) {
    this->n = n;
    for (int i = 0; i < n; i++) G[i].clear();
    edges.clear();
  }
  void AddEdge(int from, int to, int cap, int cost) {
    edges.push_back(Edge(from, to, cap, 0, cost));
    edges.push_back(Edge(to, from, 0, 0, -cost));
    m = edges.size();
    G[from].push_back(m - 2);
    G[to].push_back(m - 1);
  }
  bool BellmanFord(int s, int t, int flow_limit, int& flow, int& cost) {
    for (int i = 0; i < n; i++) d[i] = INF;
    memset(inq, 0, sizeof(inq));
    d[s] = 0;
    inq[s] = 1;
    p[s] = 0;
    a[s] = INF;
    queue<int> Q;
    Q.push(s);
    while (!Q.empty()) {
      int u = Q.front();
      Q.pop();
      inq[u] = 0;
      for (int i = 0; i < G[u].size(); i++) {
        Edge& e = edges[G[u][i]];
        if (e.cap > e.flow && d[e.to] > d[u] + e.cost) {
          d[e.to] = d[u] + e.cost;
          p[e.to] = G[u][i];
          a[e.to] = min(a[u], e.cap - e.flow);
          if (!inq[e.to]) {
            Q.push(e.to);
            inq[e.to] = 1;
          }
        }
      }
    }
    if (d[t] == INF) return false;
    if (flow + a[t] > flow_limit) a[t] = flow_limit - flow;
    flow += a[t];
    cost += d[t] * a[t];
    for (int u = t; u != s; u = edges[p[u]].from) {
      edges[p[u]].flow += a[t];
      edges[p[u] ^ 1].flow -= a[t];
    }
    return true;
  }
  int MincostFlow(int s, int t, int flow_limit, int& cost) {
    int flow = 0;
    cost = 0;
    while (flow < flow_limit && BellmanFord(s, t, flow_limit, flow, cost))
      ;
    return flow;
  }
} so;
string s;
int cnt[26];
int main() {
  cin >> s;
  int ls = s.length();
  memset(cnt, 0, sizeof(cnt));
  for (int t = (0); t < (ls); ++t) ++cnt[s[t] - 'a'];
  int n;
  cin >> n;
  string k[110];
  int a[110];
  for (int t = (0); t < (n); ++t) cin >> k[t] >> a[t];
  int st = 0;
  so.init(500);
  for (int i = 1; i <= 26; ++i) so.AddEdge(st, i, cnt[i - 1], 0);
  for (int i = 1; i <= 26; ++i) {
    for (int j = (0); j < (n); ++j) {
      int cnt = 0;
      for (auto r : k[j])
        if (r == 'a' + i - 1) ++cnt;
      so.AddEdge(i, 27 + j, cnt, j + 1);
    }
  }
  int des = 26 + n + 1;
  for (int j = (0); j < (n); ++j) {
    so.AddEdge(j + 27, des, a[j], 0);
  }
  int ans = 0;
  int flow = so.MincostFlow(st, des, INF, ans);
  if (flow != ls)
    puts("-1");
  else
    cout << ans;
}
