The epidemiologist W. Andy wants to find the index case of an ongoing crisis. To do this, he modelled the city of the outbreak and its n residents with a cellular automaton. The city is represented by n cells numbered from 1 to n and each cell has two neighbouring cells, one to its left and one to its right. The left neighbour of cell i is cell i−1 and the right neighbour is cell i+1. Additionally, the left neighbour of cell 1 is cell n and the right neighbour of cell n is cell 1. Thus, the city and the corresponding automaton form a simple cycle.
Each cell contains an integer between 1 and m which represents how likely it is that this person is infected. Since the virus can only be transmitted by personal contact, the value in the ith cell on day d only depends on the values of its neighbours and itself on the previous day. If we denote this value by s_d\[i], then the outbreak can be simulated by a function f using the formula: \[s_{d}[i]=f\big(s_{d-1}[i-1],s_{d-1}[i],s_{d-1}[i+1]\big).\] Note that as the city is cyclic both i+1 and i−1 are calculated modulo n.
Andy wants to find the index case, so he first has to find s_0, the state of the city on day zero. This poses a problem, however, as it is not known on which day the crisis started. Right now, Andy believes that he accomplished the task and found the state s_0, but you are not convinced. Therefore, you want to check if there may be a state previous to the initial state proposed by Andy, i.e. whether there exists any state s_−1 that gets transformed into s_0 by applying f.
The input consists of:
Output yes if there exists at least one possible previous state and no otherwise.