<?php

function mbStrSplit($string) {
	return preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY);
}

$string = "АРГЕНТИНА МАНИТ НЕГРА";
$stringAsArray = mbStrSplit($string);
$numberOfLetters = count($stringAsArray);

for ($i = 0; $i < $numberOfLetters; $i++) {
	echo implode(' ', $stringAsArray) . "\n";
	array_push($stringAsArray, array_shift($stringAsArray));
}