10162.cpp

#include<stdio.h>
#include<string.h>

#define MAXN 202
int A[MAXN];
int N;
char DD[MAXN];
void LastD(int n) {
      int i, j, k;
	  k = n % 10;
	  if(k == 0 || k == 1 || k == 6 || k == 5) {
		  N += k;
		  N = N %10;
          return; 		  
	  }
      j = 1;
	  for(i = 1; i<=n; i++) {
		  j *= n;
		   j %= 10;
	  }
	  N+= j;
	  N %= 10;
}



void Gen() {
 int i;
 N = 0;
	for(i = 1; i<=100; i++){
		LastD(i);
		A[i] = N;
	}

}

int KEY() {
  int i, k= 0, c = 1,sum = 0;
  int l = strlen(DD);
  for(i = l-1; i>=0; i--) {
     sum= (DD[i] - '0') * c;
     k += sum;
	 c *= 10;
	 if(c == 100) break;
  }
  return k;	 
}

int main() {
	int i;
	Gen();
    while(1) {
		 scanf("%s",DD);
		 if(!strcmp(DD,"0")) break;
		 i = KEY();
		 printf("%d\n",A[i]);
	}
	return 0;

}