#include<fstream>
using namespace std;
ifstream f("cifra.in");
ofstream g("cifra.out");
int i,t,suma,j,nr, v[21]={0,1,5,2,8,3,9,2,8,7,7,8,4,7,3,8,4,1,5,4,4};
char x,s[101];
int main()
{s[0]=48;
f>>t;
for(i=1;i<=t;i++)
{j=0;
f>>x;
while(x!='\n')
{j++;
s[j]=x;
f>>x;
}
nr=(s[j-1]-48)*10+s[j]-48;
suma=nr/20*4+v[nr%20];
suma=suma%10;
}
g<<suma;
return 0;
}