P24_LUCKY5.py

# Chef loves lucky numbers. Everybody knows that lucky numbers are positive integers whose decimal
# representation contains only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5,
# 17, 467 are not.
#
# Chef has a positive integer N. He can apply any of the following operations as many times as he want in
# any order:
#
# Add 1 to the number N.
# Take some digit of N and replace it by any non-zero digit.
# Add any non-zero leading digit to N.
# Find the minimum number of operations that is needed for changing N to the lucky number.
#
# Input
# The first line contains a single positive integer T, the number of test cases. T test cases follow. The
# only line of each test case contains a positive integer N without leading zeros.
#
# Output
# For each T test cases print one integer, the minimum number of operations that is needed for changing N
# to the lucky number.
#
# Constraints
# 1 ≤ T ≤ 10
#
# 1 ≤ N < 10100000
#
# Example
# Input:
# 3
# 25
# 46
# 99
#
# Output:
# 2
# 1
# 2

for _ in range(int(input())):
    number = input().strip()
    count = number.count('4') + number.count('7')
    print(int(len(number) - count))