hdu1061 rightmost digit

#include<cstdio>
#include<iostream>
using namespace std;
int main()
{
int c;
while(~scanf("%d",&c))
{
while(c--)
{
int n,i,b;
int a[10][4]={{0},{1},{6,2,4,8},{1,3,9,7},{6,4},
{5},{6},{1,7,9,3},{6,8,4,2},{1,9}};
cin>>n;
i=n%10;
if(i==0||i==1||i==5||i==6) b=i;
else if(i==2||i==3||i==7||i==8) b=a[i][n%4];
else if(i==4||i==9) b=a[i][n%2];
cout<<b<<endl;
}
}
return 0;
}