#include<stdio.h>
char c;
int cuv=0,l=0;
int main()
{
FILE *f=fopen("text.in","r");

while(!feof(f))
{fscanf(f,"%c",&c);


   if(c=='\n'||feof(f))break;


if(c>=65&&c<=90||c>=97&&c<=122)
    {cuv++;
     while(c>=65&&c<=90||c>=97&&c<=122)
      {l++;
       fscanf(f,"%c",&c);
       if(c=='\n'||feof(f))break;
       }
    }
}
fclose(f);
FILE *g=fopen("text.out","w");
fprintf(g,"%d",l/cuv);
fclose(g);
return 0;
}