B'You are given a positive integer n , written without leading zeroes (for example, the number 04 is incorrect). In one operation you can delete any digit of the given integer so that the result remains a positive integer without leading zeros. Determine the minimum number of operations that you need to consistently apply to the given integer n to make from it the square of some positive integer or report that it is impossible. An integer x is the square of some positive integer if and only if x=y^2 for some positive integer y . The first line contains a single integer n ( 1 <= n <= 2 cdot 10^{9} ). The number is given without leading zeroes. If it is impossible to make the square of some positive integer from n , print -1. In the other case, print the minimal number of operations required to do it. In the first example we should delete from 8314 the digits 3 and 4 . After that 8314 become equals to 81 , which is the square of the integer 9 . In the second example the given 625 is the square of the integer 25 , so you should not delete anything. In the third example it is impossible to make the square from 333 , so the answer is -1. '...