#include<fstream>

using namespace std;

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

int main()
{
    char c;
    int lungime=0,ok=0,s=0,cuv=0;
    while(fin.get(c))
    {
        if (isalpha(c)!=0 && ok==1)
            lungime++;
            else
                if(isalpha(c)!=0 && ok==0)
            {
                lungime=1;
                ok=1;
            }
            else
                if(isalpha(c)==0 && ok==1)
            {
                cuv++;
                s=s+lungime;
                lungime=0;
                ok=0;
            }
    }
    fout<<s/cuv;
}