#include <stdio.h>
#include <algorithm>
#include <deque>
using namespace std;
using ll = long long;

void solve();
int main() {
	solve();
#ifdef DBG
	while (true);
#endif
}
//18
void solve() {
	char s[1025];
	scanf("%s", s);
	for (int i = 0, c = 1; s[i] != 0; i++, c++) {
		int v = ((int) (s[i] - 'A') - c) % 26;
		if (v < 0)
			v += 26;
		s[i] = v + 'A';
	}
	printf("%s\n", s);
}