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

using namespace std;
int main()
{
    char text[1048576];
    ifstream read("text.in");
    ofstream write("text.out");
    read.getline(text, 1048576);
    unsigned int length = strlen(text);
    unsigned int i, litere = 0, cuvinte = 0;
    for(i = 0; i < length; ++i)
          if (isalpha(text[i]))
          litere++;
          else if(i>=1 && i<length && isalpha(text[i-1]) && isalpha(text[i+1]))
			  cuvinte++;
    write << litere / cuvinte;
    return 0;   
}