#include<fstream>
#include<string>
using namespace std;
char cuvant;
long i,nrlit,nrc,rez;
int main()
{
	
	FILE *f = fopen ("text.in", "r") ;
    FILE *g = fopen ("text.out", "w") ;
    while ((cuvant=fgetc(f))!=EOF)
	{
		if (( cuvant-'a'>=0 && cuvant-'a'<26 ) || ( cuvant-'A'>=0 && cuvant-'A'<26 ) )
		{
			nrc++;
			while((( cuvant-'a'>=0 && cuvant-'a'<26 ) || ( cuvant-'A'>=0 && cuvant-'A'<26 ) ) )
			{
				nrlit++;
				i++;
				cuvant=fgetc(f);
			}
		}		
	}	
	if ( nrc !=0 )
		rez=nrlit/nrc;
	fprintf(g,"%d",rez);
	

	return 0;
}