#include <fstream>
#include <cstring>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
char S[2000010],sep[]="1234567890,.;?! :-";
int nrcuv,lgtotal;
int main()
{
    fin.getline(S,2000010);
    char *p=strtok(S,sep);
    while(p!=0)
    {
        int k=0,m=strlen(p);
        for( ;k<m;k++)
        {
            if(isalpha(p[k])==0)
                while(isalpha(p[k])==0&&k<m)
                    k++;
            if(isalpha(p[k])!=0)
            {
                nrcuv++;
                while(isalpha(p[k])!=0&&k<m)
                {
                    lgtotal++;
                    k++;
                }
            }
        }
        p=strtok(NULL,sep);
    }
    fout<<lgtotal/nrcuv;
    return 0;
}