#include<iostream>
#include<sstream>
#include<stdexcept>

int main() {
    std::string line;
    int a,b;
    std::getline(std::cin,line);
    std::istringstream iss(line);
    try{
        if(!(iss>>a>>b)) {
            throw std::invalid_argument("Invalid input.");
        }
        if(b==0){
            std::cout<<"Division by zero is not allowed."<<std::endl;
        }else {
            std::cout<<(a/b)<<std::endl;
        }
    }
    catch(constmstdstd::exception& e) {
        std::cout<<"Invalid input."<<std::endl;
    }
    return 0;
}