#include <iostream>

using namespace std;

int main()

{

int a[4],b[4];

int i,j,tmp;

for (i=0;i<4;i++)

cin >> b[i];

for (i=0;i<4;i++)

{

a[i]=0;

for (j=0;j<=i;j++)

{

a[i]+=b[j];

b[a[i]%4]+=a[j];

}

}

tmp=1;

for (i=0;i<4;i++)

{

a[i]%=10;

b[i]%=10;

tmp*=a[i]+b[i];

}

cout << tmp << endl;

return 0;

}

输入：2 3 5 7

输出：_______________