alternating_chars.py

def main():
    cases = int(input())
    
    for case in range(cases):
        print(deletions(input()))
        
def deletions(s):
    
    # Set our first char
    last = s[0]
    new = last
    
    # Go through the rest of the chars
    for c in s[1:]:
        # Don't add it if it's a dupe
        if last != c:
            new += c
        last = c
        
    # Check the lengths to determine the deletions needed
    return len(s)-len(new)
    
if __name__ == '__main__':
    main()