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

FILE *f,*g;
char s[1000000],sp[256],*p;

unsigned long k,nr,i;
int main()
{
f=fopen("text.in","r");
g=fopen("text.out","w");

fgets(s,1000000,f);
//strcpy(s+strlen(s)-1,s+strlen(s));
k=0;
for(i=1;i<=255;i++)
{
    char x=i;
 if (!islower (x) && !isupper  (x)    )
 sp[k++]=x ;
}
sp[k++]='\0';
p=strtok(s,sp);
k=0;
nr=0;

while (p)
{


k+=strlen(p);
nr++;
p=strtok(0,sp);
}
fprintf(g,"%u",k/nr);
fclose(g);
return 0;
}