#include double fun(double a[], int n){ int i; double r = 0.0; for(i=0;i r+=1.0/a[i]; } return r;}int main(){ double a[10], r; int i; for(i=0;i<10;++i){ scanf("%lf", &a[i]); } r=fun(a, 10); printf("%f\n", r); return 0;}