#include<iostream>#include<string>using namespace std;class complex{public: complex(){} complex(double m,double n) { this->m=m; this->n=n; } complex &operator+(complex &s) { complex c; c.m=m+s.m; c.n=n+s.n; return c; } complex &operator-(complex &s) { complex c; c.m=m-s.m; c.n=n-s.n; return c; } complex &operator*(complex &s) { complex c; c.m=(m*s.m)-(n*s.n); c.n=(n*s.m)+(m*s.n); return c; } complex &operator/(complex &s) { complex c; c.m=((m*s.m)+(n*s.n))/(s.m*s.m+s.n*s.n); c.n=((n*s.m)-(m*s.n))/(s.m*s.m+s.n*s.n); return c; } void show() { if(m==0&&n!=0) cout<<n<<"i"<<endl; else if(n<0) cout<<m<<"-"<<n<<"i"<<endl; else if(n==0&&m!=0) cout<<m<<endl; else cout<<m<<"+"<<n<<"i"<<endl; }private: double m,n;};int main(){ int t; double m,n,m1,n1; char c; cin>>t; for(int i=0;i<t;i++) { cin>>m>>n; complex a(m,n); cin>>c; while(c!='=') { if(c=='+') { cin>>m>>n; complex b(m,n); a=a+b; } else if(c=='-') { cin>>m>>n; complex b(m,n); a=a-b; } else if(c=='*') { cin>>m>>n; complex b(m,n); a=a*b; } else if(c=='/') { cin>>m1>>n1; complex b(m1,n1); a=a/b; } cin>>c; } if(c=='=') { if(m1!=0&&n1!=0) { a.show(); continue; } else { cout<<"divide by zero"<<endl; } } } }