#include<fstream>
#define DM 1024*1100
using namespace std;

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

char C[DM];
int S,nr;

int main()
{
    int i;

    while(fin.getline(C,DM))
    {
        for(i=0;C[i];)
        {
            if((C[i]>='a' && C[i]<='z') || (C[i]>='A' && C[i]<='Z'))
            {
                while((C[i]>='a' && C[i]<='z') || (C[i]>='A' && C[i]<='Z')) {   S++; i++;   }
                nr++;
            }
            else
                i++;
        }
    }

    fout<<S/nr<<"\n";

    fin.close();
    fout.close();
    return 0;
}