#include<stdio.h>   
#include<string.h>
char s[1000000],sep[]="_ ,.?/!;\'-@#$%^&*(){}[]|:<>+~`1234567890",*a;
long long n,nr,nrc,l,i,se,j;
float r;
int main(){
	freopen("text.in","r",stdin);
	freopen("text.out","w",stdout);
	gets(s);
	n=strlen(s);
	for(i=0;i<n;i++){
		if(s[i]<='Z'&&s[i]>='A'||s[i]<='z'&&s[i]>='a')
		nr++;
	}
	a=strtok(s,sep);
	if(a!=NULL)
		nrc++;
	while(a!=NULL){
		nrc++;
		a=strtok(NULL,sep);
	}
	nrc--;
	r=nr/nrc;
	printf("%d",int(r));
	fclose(stdin);
	fclose(stdout);
	return 0;
}