#include <iostream>
#include <iomanip>
using namespace std;
void add(int a, int b, int m, int n);
void min(int a, int b, int m, int n);
void multi(int a, int b, int m, int n);
void div1(int a, int b, int m, int n);
int main() {
int a,b,m,n;
char c;
cin >> a >> b;
cin >> c;
cin >> m >> n;
switch(c) {
case '+': add(a, b, m, n); break;
case '-': min(a, b, m, n); break;
case '*': multi(a, b, m, n); break;
case '/': div1(a, b, m, n); break;
}
return 0;
}
void add(int a, int b, int m, int n) {
int l, r;
l = a + m;
r = b + n;
if (l != 0){
if (r != 0) {
if (r > 0)
cout << l << "+" << r << "i";
else
cout << l << r << "i";
}
else {
cout << l;
}
}
else {
if (r != 0) {
cout << r << "i";
}
else {
cout << 0;
}
}
}
void min(int a, int b, int m, int n) {
int l, r;
l = a - m;
r = b - n;
if (l != 0) {
if (r != 0) {
if (r > 0)
cout << l << "+" << r << "i";
else
cout << l << r << "i";
}
else {
cout << l;
}
}
else {
if (r != 0) {
cout << r << "i";
}
else {
cout << 0;
}
}
}
void multi(int a, int b, int m, int n) {
int l, r;
l = a * m - b * n;
r = a * n + b * m;
if (l != 0) {
if (r != 0) {
if (r > 0)
cout << l << "+" << r << "i";
else
cout << l << r << "i";
}
else {
cout << l;
}
}
else {
if (r != 0) {
cout << r << "i";
}
else {
cout << 0;
}
}
}
void div1(int a, int b, int m, int n) {
if (m == 0 && n == 0) {
cout << "error";
} else {
double l, r;
l = (double)(a * m + b * n) / (m * m + n * n);
r = (double)(b * m - a * n) / (m * m + n * n);
if (l != 0) {
if (r != 0) {
if (r > 0) {
cout << setprecision(1) << l << "+" << r << endl;
}
else {
cout << setprecision(1) << l << r << "i" << endl;
}
}
else {
cout << setprecision(1) << l << endl;
}
} else {
if (r != 0) {
cout << setprecision(1) << r << "i" << endl;
}
else {
cout << 0;
}
}
}
}