b

bobNum = 0
i = 0
s = 'azcbobobegghaklbob'
for char in s:
        sbob = s[i:i+3]
        if sbob == 'bob':
                bobNum += 1
        #print char, i, sbob, bobNum
        i+=1

print "Number of times bob occurs is: " + str(bobNum)