/*
text infoarena
*/

#include<vector>
#include<string>
#include<string.h>
#include<algorithm>
#include<cstdio>
#include<fstream>
#include<iostream>
#include<ctime>
#include<set>
#include<map>
#include<cmath>

using namespace std;

#define LL long long
#define PII pair<int ,int>
#define PCI pair<char ,int>
#define VB vector <bool>
#define VI vector <int>
#define VC vector <char>
#define WI vector<VI>
#define WC vector<VC>
#define RS resize
#define X first
#define Y second

#define FORN(i,n) for(int i=0;i<n;++i)
#define FOR(i,a,b) for(int i=a;i<=b;++i)
#define FORD(i,a,b) for(int i=a;i>=b;--i)
#define REPEAT do
#define UNTIL(x) while((x))

#define IN_FILE "text.in"
#define OUT_FILE "text.out"
ifstream f(IN_FILE);
ofstream g(OUT_FILE);

//variables
string text;
vector<char> chara;
LL sum;
int nr;
int cuv;
//other functions
void reading()
{
	string aux;
	while (f >> aux)
	{
		text += aux+"_";
	}
	f.close();
}
bool check(char y)
{
	FORN(i, chara.size())
	{
		if (y == chara[i])
		{
			return false;
		}
	}
	return true;
}
void solving()
{
	chara.push_back(',');
	chara.push_back('-');
	chara.push_back('.');
	chara.push_back('_');
	FORN(i, text.length())
	{
		char x = text.substr(i,1)[0];
		if (check(x))
		{
			cuv++;
		}
		else if (cuv>0)
		{
			sum += cuv;
			++nr;
			cuv = 0;
		}
	}
}
void write_data()
{
	g << sum / nr;
}
int main()
{
	reading();
	solving();
	write_data();
}