__author__='Karthik K'

'''

    I am not sure about the global current_ptr. It may crash. I made it global for the use in print_memory_map

    If you hit any issues mail to karthik3186@gmail.com

'''

import sys

SIZE=10000 #Size of the memory that will be allocated for BrainF**K

LOWER_BOUND=0 

UPPER_BOUND=SIZE-1

memory=[0]*SIZE #Actual memory been given to BrainF**K

current_ptr=0

def extract_between_brackets(source, start):

    '''

        Given a source and a starting square bracket, it gives the string between this square bracket

        and its corresponding close bracket

    '''

    openB=1

    ret=''

    cur=start+1

    while (openB!=0):

        if cur >= len(source):

           break

        if source[cur]=='[':

            openB+=1

        elif source[cur]==']':

            openB-=1

        else:

            pass

        ret+=source[cur]

        cur+=1        

    if openB!=0:

        return 'ERROR'

    return ret[0:len(ret)-1], cur

def check_and_exit_if_needed():

    if current_ptr < LOWER_BOUND or current_ptr > UPPER_BOUND:

        print "SEGMENTATION FAULT"

        sys.exit(1)

def verify_program(source):

    '''

        Given a BrainF**K source, this function verifies whether it is syntactically correct

    '''

    if extract_between_brackets('['+source+']', 0) != 'ERROR':

        return True

    return False

def execute(source):

    '''

        Given a BrainF**K source, this function executes it.

    '''

    global current_ptr

    check_and_exit_if_needed()

    if (not verify_program(source)):

        print "SYNTAX ERROR"

        return

    i=0

    while i<len(source):

        current_character=source[i]

        if current_character == '>':

            current_ptr += 1

            check_and_exit_if_needed()

        elif current_character == '<':

            current_ptr -= 1

            check_and_exit_if_needed()

        elif current_character == '+':

            memory[current_ptr]+=1

        elif current_character == '-':

            memory[current_ptr]-=1

        elif current_character == '.':

            print chr(memory[current_ptr])

        elif current_character == ',':

            pass

        elif current_character == '[':

            # Now this is where things get interesting. You have to search for the matching right '['

            # and execute the source within these brackets recursively :-)

            source_within_brackets, end = extract_between_brackets(source, i)

            if source_within_brackets == 'ERROR':

                print 'Syntax Error'

                sys.exit(1)

            while memory[current_ptr]:

                execute(source_within_brackets)

            i=end-1

        i+=1

def print_memory_map():

    global current_ptr

    for i in range(0, current_ptr):

        print '[',memory[i],']',

    print '[',memory[current_ptr],']'

if __name__ == '__main__':

    #print 'Hello World'

    execute('>+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]>++++++++[<++++>-] <.>+++++++++++[<++++++++>-]<-.--------.+++.------.--------.[-]>++++++++[<++++>- ]<+.[-]++++++++++.')

    #print_memory_map()