#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const double pi = acos(-1);
const double EPS = 1e-9;
long long binpowmod(long long a, long long b) {
  a %= MOD;
  long long ret = 1;
  while (b) {
    if (b & 1) ret = ret * a % MOD;
    a = a * a % MOD;
    b >>= 1;
  }
  return ret % MOD;
}
long long gcd(long long a, long long b) {
  if (!b) return a;
  return gcd(b, a % b);
}
const int N = 2e5 + 100;
const int E = N * 2;
class UnionFind {
 public:
  vector<int> p, rank, setSize;
  int numSets;
  UnionFind(int N) {
    setSize.assign(N, 1);
    numSets = N;
    rank.assign(N, 0);
    p.assign(N, 0);
    for (int i = 0; i < N; i++) p[i] = i;
  }
  int findSet(int i) { return (p[i] == i) ? i : (p[i] = findSet(p[i])); }
  bool isSameSet(int i, int j) { return findSet(i) == findSet(j); }
  void unionSet(int i, int j) {
    if (!isSameSet(i, j)) {
      numSets--;
      int x = findSet(i), y = findSet(j);
      if (rank[x] > rank[y]) {
        p[y] = x;
        setSize[x] += setSize[y];
      } else {
        p[x] = y;
        setSize[y] += setSize[x];
        if (rank[x] == rank[y]) rank[y]++;
      }
    }
  }
  int numDisjointSets() { return numSets; }
  int sizeOfSet(int i) { return setSize[findSet(i)]; }
};
class FenwickTree {
 public:
  int n;
  vector<int> BIT;
  FenwickTree(int _n) {
    n = _n;
    BIT.assign(n + 10, 0);
  }
  void update(int pos) {
    pos++;
    while (pos <= n) {
      BIT[pos] += 1;
      pos += pos & -pos;
    }
  }
  int query(int pos) {
    int ret = 0;
    pos++;
    while (pos > 0) {
      ret += BIT[pos];
      pos -= pos & -pos;
    }
    return ret;
  }
  int query(int l, int r) {
    int left = (l ? query(l - 1) : 0);
    int right = query(r);
    return right - left;
  }
};
int n, s, k;
vector<int> a, c;
int dp[55][4][2500];
int solveit(int i, int last, int got, int lasta) {
  if (got >= k) return 0;
  int& ret = dp[i][last][got];
  if (~ret) return ret;
  ret = 1e6;
  if (last != c[i] && lasta < a[i]) ret = solveit(i, c[i], got + a[i], a[i]);
  for (int j = 0; j < n; ++j) {
    if (c[j] != last && a[j] > lasta)
      ret = min(ret, abs(i - j) + solveit(j, c[j], got + a[j], a[j]));
  }
  return ret;
}
void solve() {
  memset(dp, -1, sizeof dp);
  cin >> n >> s >> k;
  a.assign(n, 0);
  c.assign(n, 0);
  for (int i = 0; i < n; ++i) cin >> a[i];
  string str;
  cin >> str;
  map<char, int> m;
  m['R'] = 0;
  m['G'] = 1;
  m['B'] = 2;
  for (int i = 0; i < n; ++i) c[i] = m[str[i]];
  int ans = solveit(s - 1, 3, 0, 0);
  if (ans >= 1e6) ans = -1;
  cout << ans << '\n';
}
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int tc = 1;
  while (tc--) {
    solve();
  }
}
