#include <cstdio>
#include <string>

int main() {
  char buf[2048];
  scanf("%s", buf);
  std::string s = buf;

  for (size_t i = 0; i < s.length(); ++i) {
    int z = (i+1) % 26;
    s[i] -= z;
    if (s[i] < 'A') s[i] += 26;
  }
  printf("%s\n", s.c_str());
}