# include <fstream>
# include <string.h>

using namespace std;


int main()
{
    char t[1000001];
    unsigned lit=0,cuv=0;
    ifstream fin ("text.in");
    ofstream fout("text.out");
while(fin.getline(t,1000001))
    {
        if((t[0] >= 'a' && t[0]<='z')||(t[0]>='A'&&t[0]<='Z'))
        cuv=1;
        for(int i = 0; i <strlen(t); i++)
       {
           if((t[i] >= 'a' && t[i]<='z')||(t[i]>='A'&&t[i]<='Z'))
        lit++;
        if(!((t[i] >= 'a' && t[i]<='z')||(t[i]>='A'&&t[i]<='Z')))
        cuv++;
        if(!((t[i] >= 'a' && t[i]<='z')||(t[i]>='A'&&t[i]<='Z'))&&(!((t[i+1] >= 'a' && t[i+1]<='z')||(t[i+1]>='A'&&t[i+1]<='Z'))))
        cuv--;
       }

    }

    if(cuv!=0)
    fout<<(unsigned)lit/cuv;
    else
    fout<<0;
   fin.close();
   fout.close();
    return 0;
}