#include<bits/stdc++.h> using namespace std; int main(){ int r; double PI=3.1415926,s; r=1; s=PI*r*r; cout<<s<<endl; r=3; s=PI*r*r; cout<<s<<endl; r=5; s=PI*r*r; cout<<s<<endl; r=7; s=PI*r*r; cout<<s<<endl; r=9; s=PI*r*r; cout<<s<<endl; return 0; }