#include<cstdio>
using namespace std;
FILE *f, *g;
//ifstream f("text.in");
//ofstream g("text.out");
char alfabet[]="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",X,*p;
int nrcuv,x,Sum,k,nr,q,sol;
int main ()
{
	/*
	f.get(S,1200);
	do
	{
		nr++;
	}while(!strchr(alfabet,S[nr]));
	p=strtok(S+nr," ,:;.?!-1234567890");
	while(p)
	{
		x=strlen(p);
		Sum+=x;
		k++;
		p=strtok(NULL," ,:;.?!-1234567890");
	}
	if(k==0)
		g<<0;
	else
		g<<Sum/k;
	*/
	f=fopen("text.in","r");
	g=fopen("text.out","w");
	fscanf(f,"%c",&X);
	do
	{
		if((X>='a' && X<='z') || (X>='A' && X<='Z'))
		{
			Sum++;
			if(q==0)
			{
				q=1;
				nrcuv++;
			}
		}
		else
			q=0;
	}while(fscanf(f,"%c",&X)!=EOF);
	if(nrcuv==0)
		fprintf(g,"0");
	else
	{
		sol=Sum/nrcuv;
		fprintf(g,"%d",sol);
	}
	return 0;
}