def StrToInt(input_string, bitlength):
try:<EOL><INDENT>return BVV(int(input_string.value), bitlength)<EOL><DEDENT>except ValueError:<EOL><INDENT>return BVV(-<NUM_LIT:1>, bitlength)<EOL><DEDENT>
Return True if the concrete value of the input_string ends with suffix
otherwise false.

:param input_string: the string we want to transform in an integer
:param bitlength: bitlength of the bitvector representing the index of the substring

:return BVV: bit-vector representation of the integer resulting from ythe string or -1 in bitvector representation
             if the string cannot be transformed into an integer