#include <bits/stdc++.h>
#define ff first
#define ss second
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MOD = 1e9+7;
struct mint
{
	int x;
	mint() : x(0) {}
	mint(int _x) : x(_x) {}
	mint operator + (int ot) const { return x+ot>=MOD ? x+ot-MOD : x+ot; }
	mint operator - () const { return x ? MOD-x : 0; }
	mint operator - (int ot) const { return x<ot ? x+MOD-ot : x-ot; }
	mint operator * (int ot) const { return 1ll*x*ot%MOD; }
	mint operator += (int ot) { return *this=*this+ot; }
	mint operator -= (int ot) { return *this=*this-ot; }
	mint operator *= (int ot) { return *this=*this*ot; }
	operator int() { return x; }
};

int n;
string S;

const int MAXN = 2020;

mint dp[MAXN][MAXN];
int main() {
	cin.tie(0); ios_base::sync_with_stdio(0);

	cin >> S; n = S.size();

	int k = 0;
	vector<int> V;
	
	for (int i = 0; i < n; i++) {
		int d = ((S[i] - 'A') + 4 - (i % 4)) % 4;
		V.push_back(d);

		if (V.size() >= 4) {
			int sz = V.size();
			if (V[sz - 1] == V[sz - 2] && V[sz - 1] == V[sz - 3] && V[sz - 1] == V[sz - 4]) {
				for (int t = 0; t < 4; t++) {
					V.pop_back();
				}
				++k;
			}
		}
	}

	int L = V.size();
	for (int i = 0; i <= n; i++) {
		dp[0][i] = 1;
	}
	for (int i = 1; i <= k; i++) {
		for (int j = 0; j <= L + 4 * (i - 1); j++) {
			mint prv;
			if (i == 1 && j == 0)
				prv = 1;
			else
				prv = dp[i - 1][j - 1];

			if (j == L + 4 * (i - 1))
				dp[i][j] = prv * 4;
			else
				dp[i][j] = prv * 3;
		}
		for (int j = 1; j <= n; j++)
			dp[i][j] += dp[i][j - 1];
	}
	cout << dp[k][n] << '\n';
}