#include<iostream> #include<cstring> using namespace std; char a[256]; int main() { 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; }