scanf integer with %ld %ld is not work correctly

I'm using gcc 4.4.7.

When I run below simple logic(C lang).

Then inputted '1 2'.

 int var1 = 0; 
 int var2 = 0;

 if(!scanf("%ld %ld",&var1, &var2))
 {
    printf("--- ERROR\n");
 }
 else
 {
    printf("--- var1  [%ld] \n", var1);
    printf("--- var2  [%ld] \n", var2);
 }

Result : --- var1 [0] --- var2 [2]

I already know %ld works for long int. What I realy want to know is how does scanf working in detail. This happens when I try to scan 2 or more numbers.