#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
int main(int argc, char *argv[]){
    FILE *f=fopen(argv[1],"r");
    int a,b;
    fscanf(f,"%d %d\n",&a,&b);
    char *s=malloc(a+a*b*sizeof(char));
    int i,j,k=0,m=0,n;
    char c;
    char *p=malloc(a*b*sizeof(char));
    p[0]='\0';
    for(i=0;i<=a;i++){
        if(i==a){
            if((fscanf(f,"%d %d\n",&a,&b))!=EOF){
            s=malloc(a+a*b*sizeof(char));
            s[0]='\0';
            for(j=0;j<strlen(p);j++){
                m++;
                c=p[j];
                for(n=0;n<j;n++){
                    if(c==s[n]){
                        m--;
                        break;
                    }
                }
                s[j]=c;
            }
            printf("%d\n",m);
            i=-1;
            p[0]='\0';
            s[0]='\0';
            m=0;
            k=0;
            }
            else{
                break;
            }
        }
        else{
            fgets(s,b+2,f);
            for(j=0;j<strlen(s);j++){
                c=s[j];
                if(isupper(c)){
                    p[k]=c;
                    k++;
                }
            }
            p[k]='\0';
        }

    }
    s[0]='\0';
    for(j=0;j<strlen(p);j++){
        m++;
        c=p[j];
        for(k=0;k<j;k++){
            if(c==s[k]){
                m--;
                break;
            }
        }
        s[j]=c;

    }
    printf("%d\n",m);
    /*free(s);
    free(p);
    fclose(f);*/
    return EXIT_SUCCESS;
}