How do I take the input in this case?

Question

I need to take input a pair of integer for each test case,but the test case number isn't given.i.e
SAMPLE INPUT:
1 2
3 4...
I could use cin in a for loop but how do I know when to terminate the loop?
It would be better to show the solution in C++

Answer 1

U can simply use

cin>>int1>>int2;

Answer 2

I think you want something like this:
while(cin>>i1>>i2){}