// Output a random-ish skyline of N buildings.
// (The standard "rand" function isn't very random, and filtering its output
// using modulo isn't really good enough either. Nonetheless, we can use this
// program to quickly create some random skylines over the required range of N
// values.)
#include <iostream>
#include <sstream>
#include <stdlib.h>

bool read_int(char const * arg, int & v)
{
    std::stringstream ss;
    ss << arg;
    ss >> v;
    return ss;
}

int main(int argc, char * argv[])
{
    int errors = 0;
    int N = -1;
    srand(time(0));

    if (argc != 2 || !read_int(argv[1], N) || N < 0)
    {
        ++errors;
        std::cerr << "Usage: " << argv[0] << " N";
    }
    else
    {
        int const W = 1000; 
        int const H = 100000000; 
        std::cout << N << '\n';
        while (N-- != 0)
        {
            std::cout << rand() % W << ' ' << rand() % H << "  ";
        }
        std::cout << '\n';
    }
    return errors;
}