#include<iostream> using namespace std; int main() { char a[256]; cin>>a; for(int i=0;i<strlen(a);i++){ if(a[i]=='A') cout<<"T"; else if(a[i]=='T') cout<<"A"; else if(a[i]=='C') cout<<"G"; else if(a[i]=='G') cout<<"C"; } return 0; }