#include <bits/stdc++.h>
using namespace std;
inline int rdint() {
  int X = 0, z = 0;
  char ch = 0;
  while (!isdigit(ch)) z = ch == '-' ? 1 : 0, ch = getchar();
  while (isdigit(ch)) X = (X << 1) + (X << 3) + (ch ^ 48), ch = getchar();
  return z ? -X : X;
}
int n, s, t;
const int MXN = 2050;
int num[MXN];
char col[MXN];
int f[56][MXN * 2];
inline int dis(int x, int y) {
  int ret = x - y;
  return ret > 0 ? ret : -ret;
}
inline int mymin(int x, int y) { return x < y ? x : y; }
int main() {
  register int i, j, k, ans = 188888888, sum = 0;
  n = rdint(), s = rdint(), t = rdint();
  for (i = 1; i <= n; ++i) num[i] = rdint(), sum += num[i];
  scanf("%s", col + 1);
  memset(f, 0x3f, sizeof(f));
  f[s][0] = 0;
  f[s][num[s]] = 0;
  for (i = 1; i <= n; ++i) {
    f[i][num[i]] = dis(i, s);
  }
  for (j = 1; j <= sum; ++j) {
    for (i = 1; i <= n; ++i) {
      for (k = 1; k <= n; ++k) {
        if (col[k] != col[i] && num[k] < num[i] && j >= num[i]) {
          f[i][j] = mymin(f[i][j], f[k][j - num[i]] + dis(i, k));
        }
      }
      if (j >= t) ans = mymin(ans, f[i][j]);
    }
  }
  if (ans == 188888888)
    cout << -1;
  else
    cout << ans;
  return 0;
}
