#include<cstdio> using namespace std; int main(){ double PI = 3.1415926; printf("%lf\n",PI * 1*1); printf("%lf\n",PI * 3*3); printf("%lf\n",PI * 5*5); printf("%lf\n",PI * 7*7); printf("%lf\n",PI * 9*9); return 0; }