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

char s [ 300 ] , sep [ ] = "- ,!.?;" ;

int main ( )
     {

	freopen ( "text.in" , "r" , stdin ) ;
	freopen ( "text.out" , "w" , stdout ) ;

	gets ( s ) ;

	int nr = 0 ;

	char *p ; int c = 0 ;

	p = strtok ( s , sep ) ;

	while ( p )
	  { c ++ ; nr += strlen ( p ) ; p = strtok ( NULL , sep ) ; }

	printf ( "%d" , nr / c ) ;

	return 0 ;


     }