#include <bits/stdc++.h>
using namespace std;
template <typename T>
void r1(T &x) {
  x = 0;
  char c(getchar());
  int f(1);
  for (; c < '0' || c > '9'; c = getchar())
    if (c == '-') f = -1;
  for (; '0' <= c && c <= '9'; c = getchar()) x = (x * 10) + (c ^ 48);
  x *= f;
}
const int maxn = 50 + 5;
const int maxk = 2e3 + 55;
const int maxm = maxn << 1;
const int mod = 1e9 + 7;
typedef int room[maxn];
template <int mod>
struct typemod {
  int z;
  typemod(int a = 0) : z(a) {}
  inline int inc(int a, int b) const {
    return a += b - mod, a + ((a >> 31) & mod);
  }
  inline int dec(int a, int b) const { return a -= b, a + ((a >> 31) & mod); }
  inline int mul(int a, int b) const { return 1ll * a * b % mod; }
  typemod<mod> operator+(const typemod<mod> &x) const {
    return typemod(inc(z, x.z));
  }
  typemod<mod> operator-(const typemod<mod> &x) const {
    return typemod(dec(z, x.z));
  }
  typemod<mod> operator*(const typemod<mod> &x) const {
    return typemod(mul(z, x.z));
  }
  typemod<mod> &operator+=(const typemod<mod> &x) {
    *this = *this + x;
    return *this;
  }
  typemod<mod> &operator-=(const typemod<mod> &x) {
    *this = *this - x;
    return *this;
  }
  typemod<mod> &operator*=(const typemod<mod> &x) {
    *this = *this * x;
    return *this;
  }
  int operator==(const typemod<mod> &x) const { return x.z == z; }
  int operator!=(const typemod<mod> &x) const { return x.z != z; }
};
int n, s, k;
struct Node {
  int col, v;
  inline int operator<(const Node &z) const { return v < z.v; }
} a[maxn];
int f[maxn][maxk];
signed main() {
  int i, j;
  r1(n), r1(s), r1(k);
  for (i = 1; i <= n; ++i) r1(a[i].v);
  for (i = 1; i <= n; ++i) {
    char c;
    cin >> c;
    a[i].col = (int)c;
  }
  memset(f, 0x3f, sizeof(f));
  for (i = 1; i <= n; ++i) f[i][a[i].v] = abs(i - s);
  for (int V = 1; V <= k + 50; ++V)
    for (i = 1; i <= n; ++i) {
      for (j = 1; j <= n; ++j)
        if (a[i].col != a[j].col && a[i].v < a[j].v) {
          f[j][V + a[j].v] = min(f[j][V + a[j].v], f[i][V] + abs(i - j));
        }
    }
  int ans(0x3f3f3f3f);
  for (i = 1; i <= n; ++i)
    for (j = k; j <= k + 50; ++j) ans = min(ans, f[i][j]);
  if (ans == 0x3f3f3f3f) return puts("-1"), 0;
  printf("%d\n", ans);
  return 0;
}
