#include<stdio.h>
using namespace std;
int main()
{//65-90 97-122
char c;
int i,j,chr,d,chr2;
FILE *f,*g;
f=fopen("text.in","r");
g=fopen("text.out","w");
i=0;j=0;d=0;chr=0;
while (chr!=3)
{
fscanf(f,"%c",&c);
chr2=c;
if (chr2!=chr) chr=chr2; else break;
if (((chr>=65) && (chr<=90)) || ((chr>=97) && (chr<=122))) j++; 
else if (j>0) i++;
}
fprintf(g,"%d",j/i);
fclose(f);
fclose(g);
return 0;
}