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

using ll = long long;
using db = double;

const int mod = 1e9 + 7;
int add(int x, int y) {
    x += y;
    return x >= mod ? x - mod : x;
}
void addto(int& x, int y) {
    x += y;
    if (x >= mod) x -= mod;
}
int mul(int x, int y) {
    return 1ll * x * y % mod;
}

int qpow(int a, int b) {
    int ans = 1;
    while (b) {
        if (b & 1) ans = mul(ans, a);
        a = mul(a, a);
        b >>= 1;
    }
    return ans;
}

const int maxn = 2222, f34 = mul(3, qpow(4, mod - 2));
int n;
string s;
set<string> chunkset = {"ABCD", "BCDA", "CDAB", "DABC"};
int ischunk(int j) {
    // cout << (string{s[j], s[j + 1], s[j + 2], s[j + 3]}) << " ffff\n";
    return chunkset.count(string{s[j], s[j + 1], s[j + 2], s[j + 3]});
}
int chunknum = 0;
int garbage;
int block[maxn];
int g[5][maxn];
int words[maxn][maxn];
int fuck[maxn][maxn];
int shit[maxn];
void solve() {
    int C[5][5] = {{1}, {1, 1}, {1, 2, 1}, {1, 3, 3, 1}, {1, 4, 6, 4, 1}};
    cin >> s;
    n = s.size();
    s.insert(s.begin(), ' ');

    for (int i = 1;; i++) {
        int flag = -1;
        for (int j = i * 4 - 3; j + 3 <= n; j++) {
            if (ischunk(j)) {
                flag = j;
                break;
            }
        }
        if (flag == -1)
            break;
        chunknum++;
        int j = flag;
        while (j != i * 4 - 3) {
            while (!ischunk(j - 1)) {
                char tmp = s[j];
                s[j] = s[j + 1], s[j + 1] = s[j + 2], s[j + 2] = s[j + 3];
                s[j + 3] = tmp;
            }
            j--;
        }
        while (s[j] != 'A') {
            char tmp = s[j];
            s[j] = s[j + 1], s[j + 1] = s[j + 2], s[j + 2] = s[j + 3];
            s[j + 3] = tmp;
        }
    }
    garbage = n - 4 * chunknum;
    // cerr << s << "\n";
    // cerr << chunknum << "\n";
    // cerr << garbage << "\n";
    g[0][0] = 1;
    g[1][0] = 1;
    g[2][0] = 1;
    g[3][0] = 1;
    g[4][0] = 1;
    block[0] = 1;
    vector<int>f={1};
    auto getxxxx=[&](const vector<int>&f){
        vector<int>g(f.size());
        g[0]=1;
        for(int i=0;i<f.size();i++){
            for(int j=1;i+j<f.size();j++){
                addto(g[i+j],mul(g[i],f[j]));
            }
        }
        return g;
    };
    auto polymul=[&](const vector<int>&f,const vector<int>&g){
        vector<int>h(f.size());
        for(int i=0;i<f.size();i++){
            for(int j=0;i+j<f.size();j++){
                addto(h[i+j],mul(f[i],g[j]));
            }
        }
        return h;
    };
    vector<int>h={1},g;
    for(int i=1;i<=chunknum;i++){
        f.push_back(mul(h[i-1],3));
        g=getxxxx(f);
        h=polymul(g,polymul(g,g));
        // for(int x:f)cout<<x<<" ";cout<<"\n";
        // for(int x:g)cout<<x<<" ";cout<<"\n";
        // for(int x:h)cout<<x<<" ";cout<<"\n";
    }
    auto gg=getxxxx(f);
    for(int i=1;i<=chunknum;i++){
        // cout<<f[i]<<" \n"[i==chunknum];
        f[i]=mul(f[i],mul(4,qpow(3,mod-2)));
    }
    g=getxxxx(f);

    
    for(int i=1;i<=chunknum;i++){
        // cout<<g[i]<<"\n";
    }
    words[0][0] = 1;
    for (int i = 0; i <= chunknum; i++) {
        for (int j = 1; j <= garbage; j++) {
            addto(words[i][j],words[i][j-1]);
            for (int k = 1; k <= i; k++) {
                addto(words[i][j], mul(words[i - k][j - 1], j - 1 == 0 ? g[k] :gg[k]));
                // cerr<<"sdjfa "<<f[k]<<" "<<f34<<"\n";
            }
            // cout<<words[i][j]<<" \n"[j==garbage];
        }
    }
    int ans = 0;
    for (int i = 0; i <= chunknum; i++) {
        // int gg;
        // if(i==0)gg=1;
        // else{
        //     if(garbage==0)gg=g[i];
        //     else gg=mul(g[i], f34);
        // }
        addto(ans, mul(words[chunknum - i][garbage],!garbage?g[i]:gg[i]));
    }
    cout << ans << "\n";
}
signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int t = 1;
    // cin >> t;
    while (t--) solve();
    return 0;
}
/*

1-2-3-4-5
*/

/*
 5
 3 4 1
 2 1 1
 4 5 1
 3 2 1
 3
 2 2
 3 2
 1 2
*/