Help me in solving PYTH99A problem

My issue

My code

# Solution as follows

string = 'bolloon'

# use this variable to count occurrences of o
count= 0      

for i in string:
    if i == 'o':
        # iterate througha the string, everytime you find an 'o', increase count_o by 1
        count = count + 1


Learning course: Learn Python
Problem Link: CodeChef: Practical coding for everyone