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

#define NC 1024

int main( void )
{
	char c;
	char sep[] = " ,.?-!;:+=\t\n\r\f\v0123456789{}<>\"/\'\\@`~#%^&*()";
	int nr = 0, l = 0, aux = 0;

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

	while ( scanf("%c", &c ) != EOF ) 
	{
		if ( isalpha(c) )
		{
			nr++;
			if ( aux == 0 )
			l++;
			aux = 1;
		}
		if ( strchr(sep, c) )
			aux = 0;
	}

	if ( l != 0 )
		printf("%d", nr/l );
	else printf("0");

	return 0;
}