def countUpper(s):
    count = 0
    for i in range(len(s)):
        if s[i].isupper() == True:
            count = count + 1
    return count
    
print(countUpper("Hello Everbody WOOO!")) # 6

###

def makeMatch(s1, s2):
    result = ""
    for i in range(len(s1)): # min(len(s1), len(s2))):
        c1 = s1[i]
        c2 = s2[i]
        if c1 == c2:
            result = result + c1
        else:
            result = result + "X"
    #diff = max(len(s1), len(s2)) - min(len(s1), len(s2))
    #result = result + "X" * diff
    return result

print(makeMatch("carrot", "ballot")) # "XaXXot"

###

def usesLetters(word, letters):
    for i in range(len(word)):
        if word[i] not in letters:
            return False
    return True
           
# Nested loop approach
def usesLetters(word, letters):
    for i in range(len(word)):
        found = False
        for j in range(len(letters)):
            if word[i] == letters[j]:
                found = True
        if found == False:
            return False
    return True

print(usesLetters("happy", "ahpy")) # True
print(usesLetters("happy", "ahnry")) # False
print(usesLetters("aaaaaaa", "par")) # True