#include <bits/stdc++.h>
using namespace std;

// エイリアス
using  ll = long signed long;
using ull = long unsigned long;
using  ld = long double;
using   P = pair<int, int>;
using llP = pair<ll, ll>;
using DoP = pair<double, double>;

// 汎用マクロ
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define FOREACH(i,q) for (auto &i : q)
#define UNIQUE(v) do { sort((v).begin(), (v).end()); (v).erase(unique((v).begin(), (v).end()), (v).end()); } while (false)
#define SZ(x) ((int)(x).size())
template <class T>inline bool chmin(T &a, const T b) {if (a > b) { a = b; return true;} return false;}
template <class T>inline bool chmax(T &a, const T b) {if (a < b) { a = b; return true;} return false;}
template <class T>inline void line_out(const vector<T> vec) {int n = SZ(vec); rep(i, n) { cout << vec[i]; if(i < n-1) cout << " ";}cout << endl;}
const int di[] = {0, 1, 0, -1, 1, 1, -1, -1};
const int dj[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int di2[] = {1, 1, -1, -1, 0, 1, 2, 2, 2, 2, 2, 1, 0, -1, -2, -2, -2, -2, -2, -1};
const int dj2[] = {1, -1, 1, -1, 2, 2, 2, 1, 0, -1, -2, -2, -2, -2, -2, -1, 0, 1, 2, 2};
const int INF = 1 << 28;
const ll INF64 = 1ll << 55;
const int mod = 1000000007;
//const int mod = 998244353;
struct mint
{
  ll x; // typedef long long ll;
  mint(ll x = 0) : x((x % mod + mod) % mod) {}
  mint operator-() const { return mint(-x); }
  mint &operator+=(const mint a)
  {
    if ((x += a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator-=(const mint a)
  {
    if ((x += mod - a.x) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator*=(const mint a)
  {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint a) const
  {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint a) const
  {
    mint res(*this);
    return res -= a;
  }
  mint &operator++()
  {
    if ((x += 1) >= mod)
      x -= mod;
    return *this;
  }
  mint &operator--()
  {
    if ((x += mod - 1) >= mod)
      x -= mod;
    return *this;
  }
  mint operator*(const mint a) const
  {
    mint res(*this);
    return res *= a;
  }
  mint pow(ll t) const
  {
    if (!t)
      return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1)
      a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const
  {
    return pow(mod - 2);
  }
  mint &operator/=(const mint a)
  {
    return (*this) *= a.inv();
  }
  mint operator/(const mint a) const
  {
    mint res(*this);
    return res /= a;
  }
};
ll modpow(ll a, ll n) {
  ll res = 1;
  while (n > 0) {
    if (n & 1) res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

int main(){
  string s; cin >> s;
  int n = s.size();
  vector<int> a, b, c, z;
  rep(i, n) {
    if(s[i] == 'A') a.push_back(i);
    if(s[i] == 'B') b.push_back(i);
    if(s[i] == 'C') c.push_back(i);

    if(s[i] == '?') z.push_back(i);
  }
  mint ans = 0;
  int z_size = SZ(z);
  for(auto x : b) {
    mint select_a = distance(a.begin(), lower_bound(ALL(a), x));
    mint select_z_l = distance(z.begin(), lower_bound(ALL(z), x));
    mint select_c = distance(upper_bound(ALL(c), x), c.end());
    mint select_z_r = distance(upper_bound(ALL(z), x), z.end());
 
    mint add = 0;
    add += select_a*select_c*modpow(3, z_size);
    add += select_a*select_z_r*modpow(3, z_size-1);
    add += select_z_l*select_c*modpow(3, z_size-1);
    add += select_z_l*select_z_r*modpow(3, z_size-2);
    ans += add;
  }
  for(auto x : z) {
    mint select_a = distance(a.begin(), lower_bound(ALL(a), x));
    mint select_z_l = distance(z.begin(), lower_bound(ALL(z), x));
    mint select_c = distance(upper_bound(ALL(c), x), c.end());
    mint select_z_r = distance(upper_bound(ALL(z), x), z.end());
 
    mint add = 0;
    add += select_a*select_c*modpow(3, z_size-1);
    add += select_a*select_z_r*modpow(3, z_size-2);
    add += select_z_l*select_c*modpow(3, z_size-2);
    add += select_z_l*select_z_r*modpow(3, z_size-3);
    ans += add;
  }
  cout << ans.x << endl;
}

Measured memory_bytes: 4156