#include<iostream>
#include<fstream>
#include<string>
using namespace std;
int main()
{
	int k=0,nr=0,i,j;
	char a[1000];
	ifstream fin("text.in");
	ofstream fout("text.out");
	while(fin>>a)
	{
		i=strlen(a);
		for(j=0;j<=i;j++)
		{
			if((('a'<=a[j])&&(a[j]<='z'))||(('A'<=a[j])&&(a[j]<='Z')))
			{
				k++;
				while((('a'<=a[j])&&(a[j]<='z'))||(('A'<=a[j])&&(a[j]<='Z')))
				{
					nr++;
					j++;
				}
			}
		}
	}
	cout<<nr/k;
	return 0;
}