#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using Vi = vector<int>;
using Vl = vector<ll>;
using Pii = pair<int, int>;
using Pll = pair<ll, ll>;

constexpr int I_INF = (1 << 30);
constexpr ll L_INF = (1ll << 62);

//==================================

template <std::int_fast64_t Modulus>
class ModInt {
    using i64 = std::int_fast64_t;

public:
    i64 a;

    /**
     * コンストラクタ
     */
    constexpr ModInt(const i64 x = 0) noexcept : a(x % Modulus) {}

    constexpr i64& value() noexcept { return a; }
    constexpr const i64& value() const noexcept { return a; }

    constexpr ModInt operator+(const ModInt& rhs) const noexcept {
        return ModInt(*this) += rhs;
    }
    constexpr ModInt operator-(const ModInt& rhs) const noexcept {
        return ModInt(*this) -= rhs;
    }
    constexpr ModInt operator*(const ModInt& rhs) const noexcept {
        return ModInt(*this) *= rhs;
    }
    constexpr ModInt operator/(const ModInt& rhs) const noexcept {
        return ModInt(*this) /= rhs;
    }

    constexpr ModInt& operator+=(const ModInt rhs) noexcept {
        a += rhs.a;
        if (a >= Modulus) {
            a -= Modulus;
        }
        return *this;
    }
    constexpr ModInt& operator-=(const ModInt rhs) noexcept {
        if (a < rhs.a) {
            a += Modulus;
        }
        a -= rhs.a;
        return *this;
    }
    constexpr ModInt& operator*=(const ModInt rhs) noexcept {
        a = a * rhs.a % Modulus;
        return *this;
    }
    constexpr ModInt& operator/=(ModInt rhs) noexcept {
        i64 exp = Modulus - 2;
        while (exp) {
            if (exp & 1) {
                *this *= rhs;
            }
            rhs *= rhs;
            exp >>= 1;
        }
        return *this;
    }

    constexpr ModInt& operator++() noexcept {
        *this += 1;
        return *this;
    }
    constexpr ModInt operator++(int) noexcept {
        ModInt res = *this;
        *this += 1;
        return res;
    }
    constexpr ModInt& operator--() noexcept {
        *this -= 1;
        return *this;
    }
    constexpr ModInt operator--(int) noexcept {
        ModInt res = *this;
        *this -= 1;
        return res;
    }

    constexpr bool operator<(const ModInt& rhs) const noexcept {
        return a < rhs.a;
    }
    constexpr bool operator>(const ModInt& rhs) const noexcept {
        return a > rhs.a;
    }
    constexpr bool operator<=(const ModInt& rhs) const noexcept {
        return a <= rhs.a;
    }
    constexpr bool operator>=(const ModInt& rhs) const noexcept {
        return a >= rhs.a;
    }
    constexpr bool operator==(const ModInt& rhs) const noexcept {
        return a == rhs.a;
    }

    constexpr ModInt pow(i64 k) const noexcept {
        ModInt res = 1;
        ModInt tmp = *this;
        for (; k > 0; k >>= 1) {
            if (k & 1) res *= tmp;
            tmp *= tmp;
        }
        return res;
    }

    constexpr ModInt inverse() const noexcept {
        i64 q = a;
        i64 b = Modulus, u = 1, v = 0;
        while (b) {
            i64 t = q / b;
            q -= t * b;
            swap(q, b);
            u -= t * v;
            swap(u, v);
        }
        u %= Modulus;
        if (u < 0) u += Modulus;
        return u;
    }
};

constexpr int64_t MOD = static_cast<int64_t>(1e9 + 7);

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    string S;
    cin >> S;

    int lenS = (int)S.size();

    vector<ModInt<MOD>> div(lenS);
    vector<ModInt<MOD>> a(lenS);
    vector<ModInt<MOD>> ab(lenS);
    vector<ModInt<MOD>> abc(lenS);

    div[0] = (S[0] == '?') ? 3 : 1;
    for (int i = 1; i < lenS; ++i) {
        if (S[i] == '?')
            div[i] = div[i - 1] * 3;
        else
            div[i] = div[i - 1];
    }

    a[0] = (S[0] == 'A' || S[0] == '?') ? 1 : 0;
    for (int i = 1; i < lenS; ++i) {
        if (S[i] == 'A') {
            a[i] = div[i - 1] + a[i - 1];
        }
        else if (S[i] == '?') {
            a[i] = div[i - 1] + a[i - 1] * 3;
        }
        else {
            a[i] = a[i - 1];
        }
    }

    ab[0] = 0;
    for (int i = 1; i < lenS; ++i) {
        if (S[i] == 'B') {
            ab[i] = a[i - 1] + ab[i - 1];
        }
        else if (S[i] == '?') {
            ab[i] = a[i - 1] + ab[i - 1] * 3;
        }
        else {
            ab[i] = ab[i - 1];
        }
    }

    abc[0] = 0;
    for (int i = 1; i < lenS; ++i) {
        if (S[i] == 'C') {
            abc[i] = ab[i - 1] + abc[i - 1];
        }
        else if (S[i] == '?') {
            abc[i] = ab[i - 1] + abc[i - 1] * 3;
        }
        else {
            abc[i] = abc[i - 1];
        }
    }

    cout << abc[lenS - 1].value() << endl;

    return 0;
}

Measured memory_bytes: 3664