#include <stdio.h>
int main()
{
int T,a,b;
int res = 1, ans = 0;
scanf_s("%d", &T);
for (int i = 0; i < T; i++)
{
scanf_s("%d %d", &a, &b);
for (int j = 0; j < b; j++)
{
res *= a;
res %= 10;
}
if (res == 0)
{
res = 10;
}
printf("%d\n", res);
res = 1;
}
return 0;
}