#include <stdio.h>
#include <stdlib.h>
#define MAXCIF 100
char v[MAXCIF];
int main(){
    FILE*fi,*fout;
    int s,i,j,t,p,x,i1,j1;
    char a;
    fi=fopen("cifra.in" ,"r");
    fout=fopen("cifra.out" ,"w");
    fscanf(fi,"%d" ,&t);
    a=fgetc(fi);
    for(i=0;i<t;i++){
        a=fgetc(fi);
        j=0;
        while(a>='0'&&a<='9'){
            v[j++]=a;
            a=fgetc(fi);
        }
        if(j==1)
            x=v[j-1]-'0';
        else
            x=v[j-1]-'0'+(v[j-2]-'0')*10;
        s=0;
        for(i1=1;i1<=x;i1++){
            p=1;
            for(j1=0;j1<i1;j1++)
               p=(p*i1)%10;
            s=(s+p)%10;
        }
        fprintf(fout,"%d\n" ,s);
    }
    fclose(fi);
    fclose(fout);
    return 0;
}