a=[0,233,3,2584,1346269,144,5,196418,21,1597,610,377,10946,89,514229,987,8,55,6765,2178309,121393,317811,46368,4181,1,832040,2,28657,75025,34,13,17711]
b=[0,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025,1213