spoj#ADACON. Ada and Connections
Ada and Connections
Ada the Ladybug was on a trip with her friends. They each bought a souvenir there. As all of them are mathematicians, everybody bought a number. They want to modify the numbers to have some connection between each other. They have decided to modify the numbers sou they would have their GCD greater than 1 ( gcd(a1,a2,a3,...,aN)>1). Anyway it is not easy to change a number - the only thing they can do is to go to a proffesor in mathematics, which could forge a number A into number A+1 or A-1. As this operation is not cheap, they want to minimize number of such operations. A number might be forged any number of times.
NOTE: gcd(a,0)==a (so gcd of two 0 is also 0)
Input
The first line contains an integer 1 ≤ N ≤ 3*105, the number of friend who were on trip (and also the number of numbers).
The second line contains N integers 0 ≤ ai ≤ 106
Output
Print a single line with minimum number of operations to make a connection between all numbers.
Example Input
5 3 9 7 6 31
Example Output
2
Example Input 2
9 3 4 5 7 8 9 11 12 13
Example Output 2
6
Example Input 3
5 7 7 11 17 1
Example Output 3
5