/*  Launo Tuuri --- C-ohj (Taina) s97 --- Laskarit / tehtävä:  1 / 2  */

#include <stdio.h>

int main()
{
    int m, mer;
    double riv;
    m = mer = 0;
    riv = 0.0;
    while ((m = getchar()) != EOF) {
	++mer;
	if (m == '\n') {
	    ++riv;
	    --mer;
	}
    }
    printf("kp = %.2f\n", mer/riv);
    return 0;
}