#include<iostream> using namespace std; int main(){/** int a; char ch1; cin>>a; ch1=a; cout<<ch1 char ch1,ch2; cin>>ch1>>ch2; cout<<ch1+ch2; // 字符做加法，是对应ASCII码相加 char ch1,ch2; cin>>ch1; ch2=((ch1-65)+2)%26+65; cout<<ch2; int ch1; cin>>ch1; cout<<char(ch1); float a; cin>>a; cout<<a*9/5+32; float a,b; cin>>a>>b; cout<<a*b; int a; char ch1; cin>>a; ch1=a; cout<<ch1**/ float PI=3.1415926; cout<<PE * 1*1<<endl; cout<<PI * 3*3<<endl; cout<<PE * 5*5<<endl; cout<<PE * 7*7<<endl; cout<<PE * 9*9<<endl; return 0; }