#include<fstream>
#include<cstring>
#define INFILE "text.in"
#define OUTFILE "text.out"
#define DMAX 100000

using namespace std;

ifstream fin(INFILE);
ofstream fout(OUTFILE);

char delim[] = ".,?!;:-";

int main()
{
	int lg = 0, count = 0;
	char *p;
	char sir[DMAX];
	fin >> sir;
	p = strtok_s(sir, delim, NULL);
	while (!p)
	{
		lg += strlen(p);
		count++;
		p = strtok_s(NULL, delim, NULL);
	}
	fout << lg / count << '\n';
	fin.close();
	fout.close();
	return 0;
}