Try python code

# Start coding here... 
a = bin(9)[2:]
to_return = ''
for num in a:
    if num == '1':
        to_return = to_return + '0'
    else:
        to_return = to_return + '1'

print(int(to_return,2))        

n_bina_not_flip = bin(2147483647 )[2:]
to_return = ''

if len(n_bina_not_flip) != 32:
     n_bina_not_flip = ('0'*(32-len(n_bina_not_flip))) + n_bina_not_flip
for num in n_bina_not_flip:
    if num == '1':
        to_return = to_return + '0'
    else:
        to_return = to_return + '1'
print(int(to_return,2))

num_max = max(arr) + 1
to_return = [0]*(num_max)

    #for i in range(len(arr)):
        #to_return[arr[i]] += 1
    to_return.append(len(to_return))

def countingValleys(steps, path):
    altitude = 0
    prev_altitude = 0
    num_valley = 0
    
    for i in range(steps):
        prev_altitude = altitude
        
        if path[i] == 'U':
            altitude += 1
        else:
            altitude -= 1
            
        if altitude == 0 and prev_altitude < 0:
            num_valley += 1
        
        print(altitude,prev_altitude, num_valley)

    return num_valley

countingValleys(8, 'UDDDUDUU')

list(map(chr, range(97, 123)))

for i in range(0,21,3):
    print(i)

s = 'CAA'

(s[2] != 'S') + (s[0] != 'S')