1058 N的阶乘的长度

import java.util.*;
public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner sc=new Scanner(System.in);
        while(sc.hasNext()){
            int n=sc.nextInt();
            double ans;
            int i;
            ans=1;
            for( i=1;i<=n;i++)
                ans+=Math.log10(i);
               long x=(long)ans;
            System.out.println(x);
        }
         sc.close();
        
    }

}