#include <bits/stdc++.h>
int main() {
  int n, i;
  long long cnt[5] = {0};
  char ch;
  scanf("%d", &n);
  getchar();
  cnt[0] = 1;
  for (i = 0; i < n; i++) {
    scanf("%c", &ch);
    if (ch == 'a') {
      cnt[1] = (cnt[1] + cnt[0]) % 1000000007;
    } else if (ch == 'b') {
      cnt[2] = (cnt[2] + cnt[1]) % 1000000007;
    } else if (ch == 'c') {
      cnt[3] = (cnt[3] + cnt[2]) % 1000000007;
    } else if (ch == '?') {
      cnt[3] = (3 * cnt[3] % 1000000007 + cnt[2]) % 1000000007;
      cnt[2] = (3 * cnt[2] % 1000000007 + cnt[1]) % 1000000007;
      cnt[1] = (3 * cnt[1] % 1000000007 + cnt[0]) % 1000000007;
      cnt[0] = 3 * cnt[0] % 1000000007;
    }
  }
  printf("%lld\n", cnt[3]);
  return 0;
}
