#include<bits/stdc++.h> using namespace std; int main() { char ch[256]; cin>>ch; for(int i=0;i<strlen(ch);i++) { if(ch[i]=='A') { ch[i]='T'; continue; } if(ch[i]=='T') { ch[i]='A'; continue; } if(ch[i]=='G') { ch[i]='C'; continue; } if(ch[i]=='C') { ch[i]='G'; continue; } } cout<<ch; return 0; }