#include<stdio.h>
#include<string.h>
FILE *f=fopen("text.in","r"),*g=fopen("text.out","w");
int main()
{char *p,s[1000001];
long sum=0,nr=0;
fgets(s,1000001,f);
if(s[strlen(s)-1]=='\n')
	{s[strlen(s)-1]='\0';
	}
p=strtok(s,",.!?- ");
while(p)
	{nr++;
	sum=sum+strlen(p);
	p=strtok(NULL,",.!?- ");
	}
fprintf(g,"%ld",sum/nr);
fclose(f);
fclose(g);
return 0;
}