import java.io.PrintWriter;

import java.util.*;

public class Main {

    public static final int MAXN=100+10;

    public static void main(String[] args) {

        Scanner cin = new Scanner(System.in);

        PrintWriter out = new PrintWriter(System.out);

        int n=cin.nextInt();

        long maxval=-1,val,sumval=0;

        for(int i=0;i<n;i++){

            val=cin.nextLong();

            sumval+=val;

            maxval=Math.max(maxval,val);

        }

        out.println(1L*n*maxval-sumval);

        cin.close();

        out.flush();

    }

}