K = gets.chomp.to_i
str = gets.split
X,Y = str[0].to_i, str[1].to_i
Z = X+Y
W = X.abs+Y.abs
x = 0
y = 0
q,r = 0,0
if X<0
    q = -1
else
    q = 1
end
if Y<0
    r = -1
else
    r = 1
end
if Z%2 == 1 && K%2 == 0
    puts -1
elsif W%K == 0
    puts W/K
    while (x + q*K).abs < X.abs
        x += q*K
        print x," ",y
        puts
    end
    y = r*(K-(X-x).abs)
    x = X
    print X," ",y
    puts
    while (y + r*K).abs <= Y.abs
        y += r*K
        print X," ",y
        puts
    end
elsif K%2 == 0
    a = W/K+1
    if a == 1
        a += 1
    end
    puts a
    for i in 1..a-2 do
        if (x + q*K).abs < X.abs
            x += q*K
            print x," ",y
            puts
        elsif x != X
            y = r*(K-(X-x).abs)
            x = X
            print X," ",y
            puts
        else
            y += r*K
            print X," ",y
            puts
        end
    end
    b = (2*K - (X-x).abs - (Y-y).abs)/2
    if K+b > (X-x).abs
        print x-q*b," ",y+r*(K-b)
    else
        print X-q*b," ",Y-r*(K-b)
    end
    puts
    print X," ",Y
    puts
else
    a = W/K+1
    if a%2 != W%2
        a += 1
    end
    if a == 1 && W%2 == 1
        puts 3
        x = X
        b = K-W
        y = Y + r*b
        print  x," ",y
        puts
        b = (2*K - (X-x).abs - (Y-y).abs)/2
        print X-q*b," ",y-r*(K-b)
        puts
        print X," ",Y
        puts
    else
        puts a
        for i in 1..a-2 do
            if (x + q*K).abs < X.abs
                x += q*K
                print x," ",y
                puts
            elsif x != X
                y = r*(K-(X-x).abs)
                x = X
                print X," ",y
                puts
            else
                y += r*K
                print X," ",y
                puts
            end
        end
        b = (2*K - (X-x).abs - (Y-y).abs)/2
        if K+b > (X-x).abs
            print x-q*b," ",y+r*(K-b)
        else
            print X-q*b," ",Y-r*(K-b)
        end
        puts
        print X," ",Y
        puts
    end
end