import sys

if __name__ == '__main__':
    perl_amount, color_kind_amount = map(int, input().split())
    color_counts: list[tuple[int, int]] = []
    for i in range(color_kind_amount):
        color_counts.append((i, int(input())))

    color_counts.sort(key=lambda x: x[1])

    colors: list[int] = []
    for i, color_count in color_counts:
        colors += [i + 1] * color_count
    print(colors, file=sys.stderr)
    for i in range(perl_amount // 2):
        print(colors[i], colors[i + perl_amount // 2])