#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
char c[1500000001];
int n, i, l, cuv;
int main()
{
    f.getline(c, 1000000);
    n=strlen(c);
    for(i=0; i<n; i++)
        {
            if((c[i]>='A'&&c[i]<='Z')||(c[i]>='a'&&c[i]<='z')) l++;
                else if((c[i]=='-')&&((c[i-1]>='A'&&c[i-1]<='Z')||(c[i-1]>='a'&&c[i-1]<='z'))&&((c[i+1]>='A'&&c[i+1]<='Z')||(c[i+1]>='a'&&c[i+1]<='z')))
                    cuv++;
                else if(c[i]==' '||c[i]=='.'||c[i]==','||c[i]==';') cuv++;
                else if(c[i]>=0&&c[i]<=9) {l++; cuv++;}
        }
    if(cuv==0) g<<0;
        else g<<l/cuv;
    return 0;
}