{"raw_statement":[{"iden":"statement","content":"You define a string to be a _majestic string_ if each successive character in the string comes one character later in the alphabet than the one before it. For example, _bcdef_ is a majestic string, and so is _xyz_, but _acd_ is not a majestic string. The characters also wrap from z to a, so _yzab_ is a majestic string.\n\nGiven a string $s$, figure out whether or not it is a majestic string, using the rule described above.\n\nThe only line of input contains a single string $s$.\n\nIf $s$ is a majestic string, output \"YES\" (no quotes). Otherwise, output \"NO\".\n\n"},{"iden":"input","content":"The only line of input contains a single string $s$."},{"iden":"output","content":"If $s$ is a majestic string, output \"YES\" (no quotes). Otherwise, output \"NO\"."},{"iden":"examples","content":"Inputcdefghij\nOutputYES\nInputtuvwxyzab\nOutputYES\nInputhellllo\nOutputNO\n"}],"translated_statement":null,"sample_group":[],"show_order":[],"formal_statement":"**Definitions**  \nLet $ s = s_1 s_2 \\dots s_n $ be a string of length $ n \\geq 1 $, where each $ s_i \\in \\{a, b, \\dots, z\\} $.  \nDefine the alphabetical position function $ f: \\{a, b, \\dots, z\\} \\to \\mathbb{Z} $ by $ f(c) = c - 'a' $, so $ f(a) = 0, f(b) = 1, \\dots, f(z) = 25 $.\n\n**Constraints**  \n$ 1 \\leq n \\leq 26 $\n\n**Objective**  \nDetermine whether for all $ i \\in \\{1, 2, \\dots, n-1\\} $:  \n$$\nf(s_{i+1}) \\equiv f(s_i) + 1 \\pmod{26}\n$$  \nIf true, output \"YES\"; otherwise, output \"NO\".","simple_statement":"Check if a string is majestic: each next char is the next letter in alphabet (z wraps to a). Output \"YES\" if yes, \"NO\" if no.","has_page_source":false}