Problem:
Score : 700 points

Problem Statement

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:

x_{1,j} := a_j \quad (1 \leq j \leq N)

x_{i,j} := | x_{i-1,j} - x_{i-1,j+1} | \quad (2 \leq i \leq N and 1 \leq j \leq N+1-i)

Find x_{N,1}.

Constraints

2 \leq N \leq 10^6

a_i = 1,2,3 (1 \leq i \leq N)

Input

Input is given from Standard Input in the following format:

N
a_1a_2\ldotsa_N

Output

Print x_{N,1}.

Sample Input 1

4
1231

Sample Output 1

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.

Sample Input 2

10
2311312312

Sample Output 2

0

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

/*
Anki:未済
作成日:①2020/03/02
*/

#include <stdio.h>

int main()
{
    int bingo[3][3], N, i, j, k;

    for ( i = 0; i < 3; i++ )
    {
        for ( j = 0; j < 3; j++ )
        {
            if (scanf("%d", &bingo[i][j]) != 1 ) return 0;
            else scanf("%d", &bingo[i][j]);
        }
    }
    scanf( "%d", &N );

    int b[N];
    for ( k = 0; k < N; k++ )
    {
        scanf( "%d", &b[k] );
    }

    for ( i = 0; i < 3; i++ )
    {
        for ( j = 0; j < 3; j++ )
        {
            for ( k = 0; k < N; k++ )
            {
                if ( bingo[i][j] == b[k] )
                    bingo[i][j] = 0;
            }
        }
    }

    if( bingo[0][0] + bingo[1][1] + bingo[2][2] == 0 ||
        bingo[0][2] + bingo[1][1] + bingo[2][0] == 0 ||
        bingo[0][0] + bingo[0][1] + bingo[0][2] == 0 ||
        bingo[1][0] + bingo[1][1] + bingo[1][2] == 0 ||
        bingo[0][0] + bingo[1][0] + bingo[2][0] == 0 ||
        bingo[0][1] + bingo[1][1] + bingo[2][1] == 0 ||
        bingo[0][2] + bingo[1][2] + bingo[2][2] == 0 )
    {
        printf("Yes\n");
        return 0;
    }
    printf("No\n");

    return 0;
}