user_score = 0
simon_pattern = input()
user_pattern  = input()

#user_score = sum(a==b for a, b in zip(simon_pattern, user_pattern))

for char in enumerate(list(simon_pattern)):
    if user_pattern[char[0]] == char[1]:
        user_score += 1
    else:
        break
    
print('User score:', user_score)