Why my program get Crash?

#include <stdio.h>
int main(){
    int a, b;
    scanf("%d %d", &a, &b);
    try{
        throw 1;
    }
    catch(int i){
        i++;
    }
    printf("%d", a + b);
    return 0;
}

You can not use any exceptions in your program. This is a mistake. Read FAQ first.

no message

#include <iostream.h>
int main()
{
   float a, b;
   cin >> a >> b;
   cout << a + b << endl;
   return 0;
}