#include<fstream.h>
#include<string.h>

char c[1050000];
long int i,t,l,cuv;

int main()
{	ifstream f("text.in");
	ofstream g("text.out");
	f.getline(c,1050000,EOF);

	while(c[i])
	{	t=0;
		while((c[i]>='a' && c[i]<='z') || (c[i]>='A' && c[i]<='Z'))
		{	t++;
			i++;
		}
		if(t>0){       l+=t;
				cuv++;
			}
		i++;
	}

	g<<(int)l/cuv<<"\n";
	g.close();
	f.close();
        return 0;
}