output("enter a number (!=0)");
input(max1) ;
if (max1==0) {
    output("we need two numbers at least!!!");
    abort();
}
output("enter a number (!=0)");
input(max2) ;
if (max2==0) {
    output("we need two numbers at least!!!");
    abort();
}

if (max2>max1) swap(max1, max2);

while (true) {
   output("enter a number (0 to quit)");
   input(n);
   if (n==0) break;
   if (n>max1) {
      max2=max1;
      max1=n; 
   } else if (n>max2) {
      max2=n;
   }
}
output(max1,max2);