#include <iostream>
#include <fstream>
#include <stdio.h>
#include <math.h>
using namespace std;
long long n,x,a,i;
int main()
{
    ifstream f("cifre.in");
    ofstream g("cifre.out");
    f>>n;
    for (i=1;i<=n;i++)
    {
        f>>x;
        a=a+pow(x,x);
        g<<a%10;
    }
    /*FILE *f=fopen("cifre.in","r");
    FILE *g=fopen("cifre.out","w");
    fscanf(f,"%d",&n);
    for (i=1;i<=n;i++)
    {
        fscanf(f,"%d",&x);
        a=a+pow(x,x);
        if (i==n)fprintf(g,"%d",a%10);
        else fprintf(g,"%d\n",a%10);
    }
    fclose(f);
    fclose(g);*/
    f.close();
    g.close();
    return 0;

}