#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#endif

#include <stdio.h>
#include<stdlib.h>

int main(int argc, char* argv[])
{
	unsigned long lStart, lEnd, n;

	//lStart = atol(argv[1]);
	//lEnd = atol(argv[2]);
	//n = atol(argv[3]);

	lStart = 1;
	lEnd = 50;
	n = 3;

	int no_numbers = (lEnd - lStart + 1) / n;
	printf("%d\n", no_numbers);

	for (int j = 0; j < n - 1; j++) {
		printf("%d %d\n", (int)lStart + j * no_numbers, (int)lStart + (j + 1) * no_numbers - 1);
	}

	printf("%d %d\n", (int)lStart + (n - 1) * no_numbers, (int)lEnd);
	return 0;
}