var Main = function (input) {
	var elements = input.split("");
	console.log(String.fromCharCode(elements.map(function(item, i){
		var num = elements[i].charCodeAt(0) - (i + 1);
		if (num < 65) {
			num = (num - 65) + 91;
		}
		return num;
	})));
};