#include <bits/stdc++.h>
using namespace std;
/*{{{*/  //template
#define rep(i,n) for(int i=0;i<(int)(n);i++)
constexpr int INF = numeric_limits<int>::max()/2;
constexpr long long LINF = numeric_limits<long long>::max()/3;
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define sz(x) (int)(x).size()
#define debug(x) cerr<<#x<<":"<<x<<endl
#define debug2(x,y) cerr<<#x<<","<<#y":"<<x<<","<<y<<endl
//struct fin{ fin(){ cin.tie(0); ios::sync_with_stdio(false); } } fin_;
struct Double{ double d; explicit Double(double x) : d(x){} };
ostream& operator<<(ostream& os,const Double x){ os << fixed << setprecision(20) << x.d; return os; }
template<typename T> ostream& operator<<(ostream& os,const vector<T>& vec){ os << "["; for(const auto& v : vec){ os << v << ","; } os << "]"; return os; }
template<typename T,typename U> ostream& operator<<(ostream& os,const pair<T,U>& p){ os << "(" << p.first << ","<< p.second <<")"; return os; }
template<typename T> ostream& operator<<(ostream& os,const set<T>& st){ os<<"{"; for(T v:st) os<<v<<","; os <<"}"; return os; }
template<typename T,typename U> inline void chmax(T &x,U y){ if(y>x) x = y; }
template<typename T,typename U> inline void chmin(T &x,U y){ if(y<x) x = y; }
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
ll gcd(ll a,ll b){ if(b==0) return a; else return gcd(b,a%b); }
//constexpr double eps = 1e-14; 
constexpr double eps = 1e-10; 
constexpr ll mod = 1e9+7;
const int dx[]={1,0,-1,0} ,dy[] = {0,1,0,-1};
/*}}}*/

struct RSQ{
    public:
        int n;
        vector<ll> data;
        RSQ(int n_){
            n = 1;
            while(n<n_) n*=2;
            data.resize(2*n-1);
            for(int i=0;i<2*n-1;i++) data[i]=0;
        }
        void update(int k,ll a){
            k+=n-1;
            data[k]=a;
            while(k>0){
                k=(k-1)/2;
                data[k]=(data[k*2+1]+data[k*2+2])%mod;
            }
        }
        ll query(int a,int b,int k,int l,int r){
            if(r<=a or b<=l) return 0;
            if(a<=l and r<=b) return data[k]%mod;
            else return (query(a,b,k*2+1,l,(l+r)/2)%mod+query(a,b,k*2+2,(l+r)/2,r)%mod)%mod;
        }
        ll query(int a,int b){ return query(a,b,0,0,n); }
};

ll three[100005];

int main(){
    three[0] = 1;
    for(int i=1;i<=100000;i++){
        three[i] = three[i-1] * 3 % mod;
    }
    string s;
    cin >> s;
    ll n = s.size();

    //vector<ll> a(n+1,0),b(n+1,0),c(n+1,0);

    RSQ aseg(n),bseg(n),cseg(n),qseg(n);
    for(int i=0;i<n;i++){
        if(s[i]=='A') aseg.update(i,1);
        if(s[i]=='B') bseg.update(i,1);
        if(s[i]=='C') cseg.update(i,1);
        if(s[i]=='?') qseg.update(i,1);
    }

    ll ans = 0;
    for(int i=0;i<n;i++){
        if(s[i]=='B' || s[i]=='?'){
            ll p = qseg.query(0,i);
            ll q = aseg.query(0,i);
            ll x = qseg.query(i+1,n);
            ll y = cseg.query(i+1,n);


            //cout << "::: " << p << " " <<q << " " << x << " " << y << endl;
            ll t1=0,t2=0;
            t1 = q * three[p] % mod;
            if(p-1 >= 0){
                t2 = p * three[p-1] % mod;
            }
            ll tt = (t1 + t2) % mod;

            ll t3=0,t4=0;
            t3 = y * three[x] % mod;
            if(x-1>=0){
                t4 = x * three[x-1] % mod;
            }
            ll ss = (t3 + t4) % mod;
            ll tmp = tt * ss % mod;
            ans += tmp;
            ans %= mod;
            //cout << t1 << " " << t2 << " "  << t3 << " " << t4 << endl;
        }
    }
    cout << ans << endl;
}


Measured memory_bytes: 9472