title: Problem 505
date: 2015-03-01 01:00:00
---
***
# [Problem 505](https://projecteuler.net/problem=505)
***
[Xem đề gốc (tiếng Anh)](https://projecteuler.net/problem=505)

## **Truy hồi hai chiều**

$f(0,0)=1$, $f(m,n) = f(m-2,n) + f(m-1,n) + f(m,n-2) + f(m,n-1) + f(m,n+1)$. Tính $f(10^{14},10^{14}) \pmod{10^9+7}$.

***