Score : 700 points
Given is a sequence of N digits a_1a_2\ldots a_N, where each element is 1, 2, or 3. Let x_{i,j} defined as follows:
Find x_{N,1}.
Input is given from Standard Input in the following format:
N a_1a_2\ldotsa_N
Print x_{N,1}.
4 1231
1
x_{1,1},x_{1,2},x_{1,3},x_{1,4} are respectively 1,2,3,1.
x_{2,1},x_{2,2},x_{2,3} are respectively |1-2| = 1,|2-3| = 1,|3-1| = 2.
x_{3,1},x_{3,2} are respectively |1-1| = 0,|1-2| = 1.
Finally, x_{4,1} = |0-1| = 1, so the answer is 1.
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0