#include <cstdio>
#include <iostream>
#include <string>
using namespace std;

int main() {

    char str[100] = { 0 };
    cin.getline(str, sizeof(str));

    // write your code here......
    string num1 = "";
    string num2 = "";
    int f = 0;
    for (int i = 4; str[i] != '\0'; i++) {
        if (str[i] == ' ') {
            f++;
            continue;
        }
        if (f == 0) {
            num1 = num1 + str[i];
        }
        if (f == 1) {
            num2 = num2 + str[i];
        }
    }

    int num11 = stoi(num1);
    int num22 = stoi(num2);  //将字符串转换为整型数据

    if (str[0] == 'a' || str[0] == 'A') {
        cout << num11 + num22;
    }
    if (str[0] == 's' || str[0] == 'S') {
        cout << num11 - num22;
    }
    if (str[0] == 'm' || str[0] == 'M') {
        cout << num11* num22;
    }
    if (str[0] == 'd' || str[0] == 'D') {
        if (num22 == 0) {
            cout << "Error" << endl;

        } else {
            cout << num11 / num22;
        }
    }

    return 0;
}