#include <stdio.h>
#include <string.h>
using namespace std;
FILE *fi,*fo;
char L[2000000];
char *p;
int i;
int nrlit;
int nrcuv;
int n;
char ch;
int main()
{
	fi=fopen("text.in","r");
	fo=fopen("text.out","w");
	n=0;
	while(fscanf(fi,"%c", &ch)!=EOF)
	{
		L[n]=ch;
		n++;
	}
	L[n]='\0';
	nrlit=0;
	for (i=0;L[i]!='\0';i++)
		if ((L[i]>='a' && L[i]<='z') || (L[i]>='A' && L[i]<='Z'))
			nrlit++;
		else
			L[i]=' ';
	nrcuv=0;
	p=strtok(L," ");
	while (p!=NULL)
	{
		nrcuv++;
		p=strtok(NULL," ");
	}
	fprintf(fo,"%d",nrlit/nrcuv);
	fclose(fi);
	fclose(fo);
	return 0;
}