#include <fstream>
#include <cstring>
using namespace std;

ifstream fin("text.in");
ofstream fout("text.out");

int main()
{
	int cuv = 0, sum = 0, i = 0;
	char a[256], sep[] = "<>?-;':!.,^&*()_+=}{[]\" `~/|@#$%";
	while(!fin.eof())
	{
		fin.getline(a, 256);
		char *p = strtok(a, sep);
		while( p!= NULL )
		{
			sum = sum + strlen(p);
			cuv++;
			p = strtok(NULL, sep);
		}
	}
	fout << sum / cuv;
	fin.close();
	fout.close();
	return 0;
}