#include<cstdio>
#include<string.h>
char init[128],s[128];int exp(const int val){int i=1,a1=val%10;for(i=2;i<=val;++i)a1=(a1*val)%10;return a1;}void proc(){int i;for(i=1;i<=99;++i){init[i]=(init[i-1]+exp(i))%10;/*//printf("%d ",init[i]);*/}/*//printf("\n");*/}int main(){freopen("cifra.in","r",stdin);freopen("cifra.out","w",stdout);proc();int T,pos;scanf("%d\n",&T);while(T--){fgets(s,sizeof(s),stdin);/*instead of strlen*/pos=sizeof(s)-1;while(s[pos]=='\n'||!s[pos])--pos;if(pos)printf("%d\n",init[(s[pos]-48)+(s[pos-1]-48)*10]);else printf("%d\n",init[s[0]-'0']);memset(s,0,sizeof(s));}return 0;}