#include <iostream>
#include<fstream>
#include<cstring>
using namespace std;
char sir[1000001];
int main()
{
    ifstream f("text.in");
    ofstream g("text.out");
        int r=0;
    int nc=0;
    while(!f.eof()){
    f.getline(sir,1000000);
    int lg=strlen(sir);
    for(int i=0;i<lg;++i){
        if(isalpha(sir[i])){
            r=r+1;
        }
    }
      for(int i=0;i<lg;++i){
            if(isalpha(sir[i])){
                ++nc;
                while(isalpha(sir[i])){
                    ++i;
                }
                --i;

            }
}
    }
g<<r/nc;

    return 0;
}