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

long c,l,o;

int main()
{
freopen("text.in","r",stdin);
c=l=o=0;
char s[1024];
while (!feof(stdin))
{
fgets(s,1024,stdin);
if(s[strlen(s)-1]=='\n') s[strlen(s)-1]=0;
char *p;
for(p=strtok(s," !#$%&'()*+,-./0123456789:;<=>?@[\"]^`{|}~"); p; p=strtok(NULL," #$!%&'()*+,-./0123456789:;<=>?@[\"]^`{|}~"))
//for(p=strtok(s," `~1234567890!{@#$%^&*()-}|:+?=><,./;\"_'[]"); p; p=strtok(NULL," `~1234567890!{@#$%^&_*()-}|:+?=><,\"./;'[]"))

     {                                         
     ++c;
     l+=strlen(p);
     }
}
freopen("text.out","w",stdout);
printf("%ld",l/c);
fclose(stdin);
fclose(stdout);
return 0;
}