#include <bits/stdc++.h>
using namespace std;
class classcomp {
 public:
  bool operator()(const int &l, const int &r) const { return l < r; }
};
long long mod = 1000000007;
void matrixmul(int p, int q, int r, long long *a, long long *b, long long *c) {
  int i, j, k;
  for (i = 0; i < p; i++) {
    for (j = 0; j < r; j++) {
      c[i * r + j] = 0;
      for (k = 0; k < q; k++)
        c[i * r + j] = (c[i * r + j] + a[i * q + k] * b[k * r + j]) % mod;
    }
  }
}
void exp(int q, long long *a, long long *c, long long n) {
  int i, j;
  if (n == 0) {
    for (i = 0; i < q; i++) {
      for (j = 0; j < q; j++) c[i * q + j] = 0;
      c[i * q + i] = 1;
    }
    return;
  }
  long long x[q * q];
  exp(q, a, x, n / 2);
  matrixmul(q, q, q, x, x, c);
  if (n % 2 == 1) {
    memcpy(x, c, sizeof(x));
    matrixmul(q, q, q, a, x, c);
  }
  return;
}
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  long long a[m * m];
  int i, j, l;
  char s[10];
  for (i = 0; i < m; i++)
    for (j = 0; j < m; j++) a[i * m + j] = 1;
  for (i = 0; i < k; i++) {
    scanf("%s", s);
    if ('a' <= s[0] && s[0] <= 'z')
      j = s[0] - 'a';
    else
      j = s[0] - 'A' + 26;
    if ('a' <= s[1] && s[1] <= 'z')
      l = s[1] - 'a';
    else
      l = s[1] - 'A' + 26;
    a[l * m + j] = 0;
  }
  long long ans[m * m];
  exp(m, a, ans, n - 1);
  long long ret = 0;
  for (i = 0; i < m; i++)
    for (j = 0; j < m; j++) {
      ret = (ret + ans[i * m + j]) % mod;
    }
  cout << ret << endl;
  return 0;
}
