{"raw_statement":[{"iden":"statement","content":"Stepan had a favorite string _s_ which consisted of the lowercase letters of the Latin alphabet.\n\nAfter graduation, he decided to remember it, but it was a long time ago, so he can't now remember it. But Stepan remembers some information about the string, namely the sequence of integers _c_1, _c_2, ..., _c__n_, where _n_ equals the length of the string _s_, and _c__i_ equals the number of substrings in the string _s_ with the length _i_, consisting of the **same** letters. The substring is a sequence of consecutive characters in the string _s_.\n\nFor example, if the Stepan's favorite string is equal to \"_tttesst_\", the sequence _c_ looks like: _c_ = \\[7, 3, 1, 0, 0, 0, 0\\].\n\nStepan asks you to help to repair his favorite string _s_ according to the given sequence _c_1, _c_2, ..., _c__n_."},{"iden":"input","content":"The first line contains the integer _n_ (1 ≤ _n_ ≤ 2000) — the length of the Stepan's favorite string.\n\nThe second line contains the sequence of integers _c_1, _c_2, ..., _c__n_ (0 ≤ _c__i_ ≤ 2000), where _c__i_ equals the number of substrings of the string _s_ with the length _i_, consisting of the same letters.\n\nIt is guaranteed that the input data is such that the answer always exists."},{"iden":"output","content":"Print the repaired Stepan's favorite string. If there are several answers, it is allowed to print any of them. The string should contain only lowercase letters of the English alphabet."},{"iden":"examples","content":"Input\n\n6\n6 3 1 0 0 0\n\nOutput\n\nkkrrrq\n\nInput\n\n4\n4 0 0 0\n\nOutput\n\nabcd"},{"iden":"note","content":"In the first test Stepan's favorite string, for example, can be the string \"_kkrrrq_\", because it contains 6 substrings with the length 1, consisting of identical letters (they begin in positions 1, 2, 3, 4, 5 and 6), 3 substrings with the length 2, consisting of identical letters (they begin in positions 1, 3 and 4), and 1 substring with the length 3, consisting of identical letters (it begins in the position 3)."}],"translated_statement":null,"sample_group":[],"show_order":[],"formal_statement":null,"simple_statement":null,"has_page_source":false}