#include using namespace std; #define ll long long #define MOD 1000000007 string s; int q; vector ps[100005]; int l,r; ll fakto[100005]; void pre() { fakto[0]=1; for(int i=1;i<=100000;i++) { fakto[i]=i*fakto[i-1]; fakto[i]%=MOD; } return; } ll fe(int x, int y) { if(y==0) return 1; if(y==1) return x; ll ret=fe(x,y/2); ret*=ret; ret%=MOD; if(y%2==1) ret*=(ll)x; ret%=MOD; return ret; } int main() { pre(); vector tmp; for(int i=0;i<26;i++) tmp.push_back(0); ps[0]=tmp; cin >> s; int id=0; for(int i=0;i0) cur*=fe(fakto[tmp/2],MOD-2); cur%=MOD; } //cout << cur << endl; if(ans==0) ans=1; ans*=fakto[dob]; ans%=MOD; ans*=cur; ans%=MOD; printf("%lld\n",ans); } return 0; }