#include <bits/stdc++.h>
using namespace std;
template <class T>
void debug(T e) {
  cout << e << endl;
}
template <class T1, class T2>
void debug(T1 e1, T2 e2) {
  cout << e1 << "\t" << e2 << endl;
}
template <class T1, class T2, class T3>
void debug(T1 e1, T2 e2, T3 e3) {
  cout << e1 << "\t" << e2 << "\t" << e3 << endl;
}
template <class T1, class T2, class T3, class T4>
void debug(T1 e1, T2 e2, T3 e3, T4 e4) {
  cout << e1 << "\t" << e2 << "\t" << e3 << "\t" << e4 << endl;
}
template <class T1, class T2, class T3, class T4, class T5>
void debug(T1 e1, T2 e2, T3 e3, T4 e4, T5 e5) {
  cout << e1 << "\t" << e2 << "\t" << e3 << "\t" << e4 << "\t" << e5 << endl;
}
template <class T>
void debug(vector<T> e) {
  int i;
  for (i = 0; i < (int)e.size(); i++) cout << e[i] << " ";
  cout << endl;
}
template <class T>
void debug(vector<T> e, int n) {
  int i;
  for (i = 0; i < n; i++) cout << e[i] << " ";
  cout << endl;
}
template <class T>
void debug(vector<basic_string<T> > e) {
  int i, j;
  for (i = 0; i < (int)e.size(); i++) {
    for (j = 0; j < (int)e[i].size(); j++) cout << e[i][j];
    cout << endl;
  }
  cout << endl;
}
template <class T>
void debug(vector<basic_string<T> > e, int row, int col) {
  int i, j;
  for (i = 0; i < row; i++) {
    for (j = 0; j < col; j++) cout << e[i][j];
    cout << endl;
  }
  cout << endl;
}
template <class T>
void debug(vector<vector<T> > e, int row, int col) {
  int i, j;
  for (i = 0; i < row; i++) {
    for (j = 0; j < col; j++) cout << e[i][j] << "\t";
    cout << endl;
  }
  cout << endl;
}
template <class T>
void debug(T e[100][100], int row, int col) {
  int i, j;
  for (i = 0; i < row; i++) {
    for (j = 0; j < col; j++) cout << e[i][j] << " ";
    cout << endl;
  }
}
template <class T>
void debug(T e[], int row) {
  int i;
  for (i = 0; i < row; i++) cout << e[i] << " ";
  cout << endl;
}
template <class T>
T Abs(T x) {
  return x > 0 ? x : -x;
}
template <class T>
inline T sqr(T x) {
  return x * x;
}
template <class T>
inline bool isPrime(T n) {
  if (n <= 1) return false;
  for (T i = 2; i * i <= n; i++)
    if (n % i == 0) return false;
  return true;
}
template <class T>
inline T Mod(T n, T m) {
  return (n % m + m) % m;
}
template <class T>
string toString(T n) {
  ostringstream oss;
  oss << n;
  oss.flush();
  return oss.str();
}
int toInt(string s) {
  int r = 0;
  istringstream sin(s);
  sin >> r;
  return r;
}
long long toLl(string s) {
  long long r = 0;
  istringstream sin(s);
  sin >> r;
  return r;
}
bool IsVowel(char ch) {
  ch = tolower(ch);
  if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u')
    return true;
  return false;
}
bool isUpperCase(char c) { return c >= 'A' && c <= 'Z'; }
bool isLowerCase(char c) { return c >= 'a' && c <= 'z'; }
long long Pow(long long B, long long P) {
  long long R = 1;
  while (P > 0) {
    if (P % 2 == 1) R = (R * B);
    P /= 2;
    B = (B * B);
  }
  return R;
}
int BigMod(long long B, long long P, long long M) {
  long long R = 1;
  while (P > 0) {
    if (P % 2 == 1) {
      R = (R * B) % M;
    }
    P /= 2;
    B = (B * B) % M;
  }
  return (int)R;
}
long long mulmod(long long a, long long b, long long c) {
  long long x = 0, y = a % c;
  while (b > 0) {
    if (b % 2 == 1) {
      x = (x + y) % c;
    }
    y = (y * 2) % c;
    b /= 2;
  }
  return x % c;
}
void binprint(long long mask, long long n) {
  long long i;
  string s = "";
  do {
    s += (mask % 2 + '0');
    mask /= 2;
  } while (mask);
  reverse(s.begin(), s.end());
  s = string(max(n - (int)s.size(), 0LL), '0') + s;
  for (i = (int)s.size() - n; i < (int)s.size(); i++) printf("%c", s[i]);
  printf("\n");
}
void ASCII_Chart() {
  int i, j, k;
  printf("ASCII Chart:(30-129)\n");
  for (i = 30; i < 50; i++) {
    for (j = 0; j < 5; j++) {
      k = i + j * 20;
      printf("%3d---> '%c'   ", k, k);
    }
    printf("\n");
  }
}
vector<string> SubstringGenerate(string str) {
  int i, j, len;
  vector<string> store;
  len = (int)str.size();
  for (i = 0; i < len; i++)
    for (j = i; j < len; j++) store.push_back(str.substr(i, j - i + 1));
  return store;
}
double deg2rad(double x) { return (3.141592653589793 * x) / 180.0; }
double rad2deg(double x) { return (180.0 * x) / 3.141592653589793; }
char mat[50][50];
int store[128], flag[128];
char query[1000000];
int main() {
  int i, j, k, test, Case = 1, check, cnt, row, col, x, c1, len, p, q, dist;
  while (scanf("%d %d %d", &row, &col, &x) == 3) {
    memset(store, 0, sizeof(store));
    memset(flag, 0, sizeof(flag));
    for (i = 0; i < row; i++) {
      scanf("%s", mat[i]);
    }
    c1 = 0;
    for (i = 0; i < row; i++) {
      for (j = 0; j < col; j++) {
        if (mat[i][j] != 'S') {
          store[mat[i][j]] = 1;
          flag[mat[i][j]] = 1;
        } else
          c1 = 1;
      }
    }
    for (i = 0; i < 128; i++)
      if (flag[i] && c1) flag[i - 32] = 1;
    for (i = 'A'; i <= 'Z'; i++) {
      for (j = 0; j < row; j++) {
        for (k = 0; k < col; k++) {
          if (mat[j][k] - 32 == i) {
            for (p = 0; p < row; p++) {
              for (q = 0; q < col; q++) {
                if (mat[p][q] == 'S') {
                  dist = sqr(abs(p - j)) + sqr(abs(q - k));
                  if (dist <= x * x) store[i] = 1;
                }
              }
            }
          }
        }
      }
    }
    scanf("%d", &len);
    scanf("%s", query);
    cnt = 0;
    check = 1;
    for (i = 0; i < len; i++) {
      if (flag[query[i]] == 0) check = 0;
      if (store[query[i]] == 0) {
        cnt++;
      }
    }
    if (check)
      printf("%d\n", cnt);
    else
      printf("-1\n");
  }
  return 0;
}
