#include <iostream>
  using namespace std;
  int main()
  {
  int p,c,m,err=0;
  string name;  
  do
  {
  try //using try block to check error;
  {
  cout<<"Enter sudentname : ";
  cin>>name;
  cout<<"Enter physics marks : ";
  cin>>p;     
  if(!(p>=0 && p<=100)) //checking that marks entered is valid or not;
  {
  throw(p); //using throw block to transfer error to catch block;
  }
  cout<<"Enter chemistry marks : ";
  cin>>c;     
  if(!(c>=0 && c<=100)) //checking that marks entered is valid or not;
  {
  throw(c); //using throw block to transfer error to catch block;
  }     
  cout<<"Enter mathsmarks : ";
  cin>>m;     
  if(!(m>=0 && m<=100)) //checking that marks entered is valid or not;
  {
  throw(m); //using throw block to transfer error to catch block;
  }
  err=0; //if all the conditions are false then value of error variable is 0
  }
  catch(int e)
  {
  cout<<"Invalid Marks"<<endl; //Showing error;
  err=1; //Changing value of variable to retke input;
  }
  }while(err); //it takes input until all inputs are valid;
  }