#include <bits/stdc++.h> using namespace std; int main(){ string s1, s2; cin >> s1; for(int i = 0; i < s1.length(); i++){ if(s1[i] == 'T'){ s2[i] = 'A'; }else if(s1[i] == 'A'){ s2[i] = 'T'; }else if(s1[i] == 'G'){ s2[i] = 'C'; }else{ s2[i] = 'G'; } cout << s2[i]; } return 0; }