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

int get_prio (char c) {
	int r = (int) (c - 'a'+1);
	if (r > 0) return r;
	return r + 'A' - 7;
}

int main () {
	char cur[50];
	int half = 0;
	u_int64_t masks[3] = {0};
	int sum = 0;
	int j =0;
	while (fgets(cur,50,stdin) != NULL) {
		int i;
		for (i=0; i<strlen(cur)-1; i++) {
			masks[j] |= (1LL << get_prio(cur[i]));
		}
		if (j == 2) {
			u_int64_t mask = 0;
			mask = masks[0] & masks[1] & masks[2];
			for (int k=0; k<3; k++) masks[k] = 0;
			int k =-1;
			while (mask > 0) {
				k++;
				mask >>=1LL;
			}
			sum += k;
			j = -1;
		}
		j++;
	}
	printf("%d\n", sum);

}