#include <stdio.h>
#include <ctype.h>

int  i, ii, j;
char ch;
long nr;
long sznr, bnr;

int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);

    i=0;
    ii=0;
    bnr=0;
    while (!feof(stdin))
    {
	scanf("%c", &ch);
	if (isalpha(ch)) {i=1;j=0;ii=1;}
	else {i=0;j=1;}

	if (i) {nr++;}
	if (ii && !i && j) {sznr++;ii=0;bnr+=nr;nr=0;}
    }
    if (isalpha(ch)){ bnr+=nr;sznr++; }
    

    printf("%ld", bnr/sznr);

    fclose(stdin);
    fclose(stdout);

    return 0;
}