#include <bits/stdc++.h>
using namespace std;
int n, st, m, ans, r[101], f[101][3001];
char s[101];
int main() {
  scanf("%d%d%d", &n, &st, &m);
  for (int i = 1; i <= n; i++) scanf("%d", &r[i]);
  scanf("%s", s);
  memset(f, 0x3f, sizeof(f));
  for (int i = 1; i <= n; i++) f[i][r[i]] = abs(i - st);
  for (int j = 1; j <= m + 50; j++)
    for (int i = 1; i <= n; i++)
      for (int k = 1; k <= n; k++)
        if ((s[i - 1] != s[k - 1]) && (r[i] < r[k]))
          f[k][j + r[k]] = min(f[k][j + r[k]], f[i][j] + abs(i - k));
  ans = 0x3f3f3f3f;
  for (int i = 1; i <= n; i++)
    for (int j = m; j <= m + 50; j++) ans = min(ans, f[i][j]);
  if (ans == 0x3f3f3f3f) ans = -1;
  printf("%d", ans);
}
