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


FILE *f,*g;
char s[1000000],sp[]=" ,.;:-?!",*p;

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

fgets(s,1000000,f);
strcpy(s+strlen(s)-1,s+strlen(s));
p=strtok(s,sp);
k=0;
nr=0;

while (p)
{


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