//Q412 Pi //Accepted 2008-04-20 11:18:00 #include <iostream> #include <iomanip> #include <cmath> #include <stdio.h> using namespace std; int gcd(int, int); int p[32768]; int main(void) { int t = 0, n[50]; double pi, tt, bp = 0; while(cin >> t) { bp = 0; if (t == 0) exit(0); for(int i = 0; i < t; i++) cin >> n[i]; for(int i = 2; i <= t; i++) for(int j = 1; j <= i - 1; j++) if (n[j - 1] > n[i - 1]) { if (gcd(n[j - 1], n[i - 1]) == 1) bp++; } else { if (gcd(n[i - 1], n[j - 1]) == 1) bp++; } tt = t * (t - 1) / 2; if (bp == 0) cout << "No estimate for this data set." << endl; else { pi = sqrt(...