#include <array>
#include <iostream>

constexpr std::size_t kSize = 10;

void PrintHalf(char *a, char *b, char *c, char *buffer, std::size_t size) {
  while (b != c) {
    --a;
    *a = '/';
    *b = '\\';
    std::cout.write(buffer, size);
    *b = ' ';
    *a = ' ';         
    ++b;
  }
}

int main() {
  std::array<char, kSize * 2 + 1> buffer;
  buffer.fill(' ');
  buffer.back() = '\n';

  auto first = buffer.begin();
  auto mid = first + kSize;
  auto last = mid + kSize;
  auto size = buffer.size();

  PrintHalf(mid, mid, last, first, size);
  PrintHalf(last, first, mid, first, size);
}