#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ cout<<3.1415926*(1*1)<<endl; cout<<3.1415926*(3*3)<<endl; cout<<3.1415926*(5*5)<<endl; cout<<3.1415926*(7*7)<<endl; cout<<3.1415926*(9*9)<<endl; return 0; }