World of Cartoon

World of Cartoon Shinchan and Oggy play a game. For every integer X Shinchan gives, Oggy has to find the smallest positive integer Y, such that X * Y contains only 4's and 0's and starts with one or more 4's followed by zero or more 0's. (i.e.), 404 is an invalid number but 400 is a valid number. If a is the number of 4's and b is the number of 0's, can you print the value of 2 * a + b. In