#include<iostream>
using namespace std;
int main()
{
    float k=8.99*10**9,q1,d,f;
    cout<<"Enter the Charge and Distance Values"<<endl;
    cin>>q1;
    cin>>d;
    f=k*(q1*q1)/(d*d);
    cout<<"The Electric force is:"<<f<<endl;
    if(f==0||f<0)
    cout<<"Invalid input"<<endl;
    
}