#include <iostream> #include <string> using namespace std; int main() { string s; cin >> s; for (int i = 0; i < s.size(); i++) { if (s[i] == 'A') s[i] = 'T'; else if (s[i] == 'T') s[i] = 'A'; else if (s[i] == 'G') s[i] = 'C'; else if (s[i] == 'C') s[i] = 'G'; } cout << s << endl; return 0; }