#include <fstream>
#include<string.h>
using namespace std;
ifstream in("text.in");
ofstream out("text.out");
int main()
{
    char a;
    int ok,nl=0,nc=0;
    while(in.get(a))
    {
        while(!isalpha(a))
        {
            in.get(a);
            if(a=='\n') break;
        }
        while(isalpha(a))
        {
            in.get(a);
            nl++;
        }
        nc++;
    }
    out<<nl/nc;
    return 0;
}