M3TILE - LATGACH3
Đọc đề đẹp hơn ở: https://codeforces.com/group/FLVn1Sc504/contest/274710/problem/L https://codeforces.com/group/FLVn1Sc504/contest/274501/problem/Y
In how many ways can you tile a 3xn rectangle with 2x1 dominoes? Here is a sample tiling of a 3x12 rectangle. Input consists of several test cases followed by a line containing -1. Each test case is a line containing an integer 0 ≤ n ≤ 30. For each test case, output one integer number giving the number of possible tilings.
2 8 12 -1
3 153 2131
Simple dp, you have to do case analysis a lot to crack this problem