SP1455 ANALYSER - Program Analyser

N/A

A Program which has the following format: ``` ::={} ::= ::= | | | | ::=+ ::=? ::=GO ::=IF= ::=END ::= ::= ::={} ::=A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z ::= 0|1|2|3|4|5|6|7|8|9 ::=(ASCII 10) ::=(ASCII 32) ``` The program runs following the following rules: - Program starts from the sentence whose level is minimum, and executed by the level from low to high except that the sentence isor. - All variables are initialized to 0. - means+=in C++. - means write the value ofto the output file(we aren't interesting about the real output file.) - means if and only if the value of the equals to , will be executed, otherwise the next sentence executed is as usual. - After, the next sentence executed is the sentence with level which equals to the level in. - Program terminates by itself when is executed. - The numbers during the program is running will fit in a signed 32-bit integer. - The number of sentences in the program is not more than 100. - The length of each line in the input file is not more than 20. - The input is correct. - The sentence with the maximum level is always . - Any level is not more than 3000.

Output the number of sentences executed.If the program can not terminate by itself,output -1.