#include<fstream>
#include<iostream>
#include<string.h>
#include<ctype.h>
using namespace std;

ifstream f("text.in");
ofstream g("text.out");

char x[1000005];
int cuvinte, litere,i;

int main()
{
	char *p;
	int r=0;
	

	int ok=1;
	
	for(i=1; f.get(x[i]); i++)
	{
		while(isspace(x[i]))
		{	ok=0;
			i++;
			f.get(x[i]);
		}

		while(!isalpha(x[i]) )
		{
			i++;
			f.get(x[i]);
		}
		if(isalpha(x[i]))
		{cuvinte++;
		
			while(isalpha(x[i]))
		{
			litere++;
			i++;
			f.get(x[i]);
		}
			
		}
	}

	g<<litere/(cuvinte-1);

return 0;
}