{"trustable":false,"sections":[{"title":"","value":{"format":"HTML","content":"A palindrome is a string that reads same in both directions: forwards and backwards. For example, the strings \u003cb\u003eradar\u003c/b\u003e and \u003cb\u003enoon\u003c/b\u003e are palindromes, whereas the string \u003cb\u003echef\u003c/b\u003e is not a palindrome as being read backwards is becomes equal to \u003cb\u003efehc\u003c/b\u003e, which is not equal to \u003cb\u003echef\u003c/b\u003e.\u003cbr\u003e\u003cbr\u003e\n\nLet\u0027s say that the pair of indices \u003cb\u003e(i, j)\u003c/b\u003e \u003ci\u003edenotes a palindrome\u003c/i\u003e in some string \u003cb\u003eS\u003c/b\u003e iff \u003cb\u003ei ≤ j\u003c/b\u003e and the substring starting at the \u003cb\u003ei\u003c/b\u003e-th character and ending at the \u003cb\u003ej\u003c/b\u003e-th character of \u003cb\u003eS\u003c/b\u003e is a palindrome.\u003cbr\u003e\u003cbr\u003e\n\nGiven an integer \u003cb\u003eN\u003c/b\u003e. Your task is to construct a string \u003cb\u003eS\u003c/b\u003e such that there are exactly \u003cb\u003eN\u003c/b\u003e different pairs \u003cb\u003e(i, j)\u003c/b\u003e that denotes a palindrome."}},{"title":"Input","value":{"format":"HTML","content":"The first line of the input contains an integer \u003ci\u003eT\u003c/i\u003e (1 ≤ \u003ci\u003eT\u003c/i\u003e ≤ 10) denoting the number of test cases. The description of \u003ci\u003eT\u003c/i\u003e test cases follows.\u003cbr\u003e\u003cbr\u003e\n\nThe first line of each test case contains a single integer \u003ci\u003eN\u003c/i\u003e (1 ≤ \u003ci\u003eN\u003c/i\u003e ≤ 10\u003csup\u003e4\u003c/sup\u003e) denoting the sought number of pairs that denote palindrome."}},{"title":"Output","value":{"format":"HTML","content":"For each test case, output a single line containing a string \u003cb\u003eS\u003c/b\u003e, consisting of lowecase Latin letters, and having exactly \u003cb\u003eN\u003c/b\u003e distinct palindrome-denoting pairs. If there\u0027s a few such strings, output any one. If such string \u003cb\u003eS\u003c/b\u003e doesn\u0027t exist, output \u003cb\u003e-1\u003c/b\u003e instead of it."}},{"title":"Examples","value":{"format":"HTML","content":"\u003ctable border\u003d\"1px solid\" width\u003d\"100%\" cellpadding\u003d\"4px\" cellspacing\u003d\"0px\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth width\u003d\"50%\"\u003eSample Input\u003c/th\u003e\n \u003cth width\u003d\"50%\"\u003eSample Output\u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign\u003d\"top\"\u003e\u003ccode\u003e\n3\u003cbr\u003e\n6\u003cbr\u003e\n7\u003cbr\u003e\n2\u003cbr\u003e\n \u003cbr\u003e\u003c/code\u003e\u003c/td\u003e\n \u003ctd valign\u003d\"top\"\u003e\u003ccode\u003e\nnoon\u003cbr\u003e\nradar\u003cbr\u003e\nab\u003cbr\u003e\n \u003cbr\u003e\u003c/code\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}},{"title":"Explanation","value":{"format":"HTML","content":"\u003cb\u003eExample case 1.\u003c/b\u003e In the string \"noon\", the pairs that denote a palindrome are (1-indexed): \u003cb\u003e(1, 1), (1, 4), (2, 2), (2, 3), (3, 3), (4, 4)\u003c/b\u003e.\u003cbr\u003e\u003cbr\u003e\n\u003cb\u003eExample case 2.\u003c/b\u003e In the string \"radar\", the pairs that denote a palindrome are (1-indexed): \u003cb\u003e(1, 1), (1, 5), (2, 2), (2, 4), (3, 3), (4, 4), (5, 5)\u003c/b\u003e.\u003cbr\u003e\u003cbr\u003e\n\u003cb\u003eExample case 3.\u003c/b\u003e In the string \"ab\", the pairs denoting a palindrome are : \u003cb\u003e(1, 1), (2, 2)\u003c/b\u003e"}}]}