//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using namespace std;
using ll = int64_t;
using ld = long double;
using P = pair<int, int>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T> >;
const int INF = 100010001;
const ll LINF = (ll)INF*INF*10;
template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true);}
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true);}
template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}

const int mod = 1000000007;
//const int mod = 998244353;

struct mint {
    int64_t x;
    mint(int64_t 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 { return mint(*this) += a;}
    mint operator-(const mint a) const { return mint(*this) -= a;}
    mint operator*(const mint a) const { return mint(*this) *= a;}
    mint pow(int64_t 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) {return mint(*this) /= a;}
};

istream& operator>>(istream& is, mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    string s;
    cin >> s;
    int n;
    n = s.size();

    vector<int> abc[4];
    rep(i, 4) abc[i].resize(n+1);

    auto add = [&](int aq, int i, int x) {
        while(i <= n) {
            abc[aq][i] += x;
            i += i&-i;
        }
    };
    auto sum = [&](int aq, int i) {
        int res = 0;
        while(i) {
            res += abc[aq][i];
            i &= i-1;
        }
        return res;
    };

    rep(i, n) {
        switch(s[i]) {
            case 'A':add(0, i+1, 1); break;
            case 'B':add(1, i+1, 1); break;
            case 'C':add(2, i+1, 1); break;
            default:add(3, i+1, 1); break;
        }
    }

    int cnt = sum(3, n);

    mint ans = 0;
    rep(i, n) {
        if(s[i] == 'B') {
            ans += mint(sum(2, n) - sum(2, i+1)) * sum(0, i) * mint(3).pow(cnt);
            if(cnt) ans += (mint(sum(2, n) - sum(2, i+1))*sum(3, i) + mint(sum(3, n) - sum(3, i+1))*sum(0, i)) * mint(3).pow(cnt-1);
            if(cnt > 1) ans += mint(sum(3, n) - sum(3, i+1))*sum(3, i) * mint(3).pow(cnt-2);    
        } else if(s[i] == '?') {
            if(cnt) ans += mint(sum(2, n) - sum(2, i+1)) * sum(0, i) * mint(3).pow(cnt-1);
            if(cnt > 1) ans += (mint(sum(2, n) - sum(2, i+1))*sum(3, i) + mint(sum(3, n) - sum(3, i+1))*sum(0, i)) * mint(3).pow(cnt-2);
            if(cnt > 2) ans += mint(sum(3, n) - sum(3, i+1))*sum(3, i) * mint(3).pow(cnt-3); 
        }
    }
    cout << ans << endl;
}

Measured memory_bytes: 5008