N, M, K = gets.split.map(&:to_i)

min_sep, max_sep = [N, M].minmax
sep = min_sep + [min_sep + 1, max_sep].min

C = K + 1

if sep < C
    puts -1
    exit
end

if C.even?
    puts "0" * (N - (C / 2 - 1)) + "10" * (C / 2 - 1) + "1" * (M - (C / 2 - 1))
elsif N == C / 2
    puts "10" * (C / 2) + "1" * (M - C / 2)
else
    puts "0" * (N - C / 2) + "10" * (C / 2 - 1) + "1" * (M - (C / 2 - 1)) + "0"
end