#include <stdio.h>

int main(void){
	int i,j,n,t,k,r = 0,c,a[16][131072] = {0},ap[16] = {0},al[131072],bl[131072],blc=0,con;
	scanf("%d",&n);
	for(i = 1;i <= n;i++){
		scanf("%d",&t);
		al[i] = t;
		k = t % 10;
		a[k][(ap[k])] = t;
		ap[k]++;
	}
	for(i = 1;i <= n;i++){
		con = 0;
		k = al[i] % 10;
		c = 0;
		for(j = 0;j < blc;j++){
			if(bl[j] == al[i]){con++;break;}
		}
		if(con){continue;}
		for(j = 0;j < ap[k];j++){
			if(al[i] == a[k][j]){c++;}
		}
		if(c == 1){r++;}
		else{bl[blc] = al[i];blc++;}
	}
	printf("%d\n",r);
	return 0;
}