DO there exist positive integers m and n so that 76^m-34^n=10398457338?

I am looking for m and n that would solve this equation. I know that I need to work mod 5. So 76 is 1 (mod 5) and 34 is 4 (mod 5) and 10398457338 is 3 (mod 5) but how do i really solve for m and n,