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

FILE *inp1, *inp2, *oup;
char str1[1024] = "", str2[1024] = "";

void strip()
{
	char temp[1024] = "", temp2[1024] = "";
	int i, j, k, result = 0, res1 = 0, res2 = 0;
	for(i = 0, k = 0; str1[i] != 0; i++)
	{
		for(j = 0, result = 0; str2[j] != 0 && result != 1; j++)
		{
			if(str1[i] == str2[j])
			{
				temp[k] = str1[i];
				k++;
				result = 1;
			}
		}
	}
	
	temp[k] = 0;
	
	for(i = 0; temp[i] != 0; i++)
	{
		str1[i] = temp[i];
	}
	
	for(i = 0; i < 1023; i++, temp[i] = 0)
	{ }
	
	temp[0] = 0;
	
	for(i = 0, k = 0; str2[i] != 0; i++)
	{
		for(j = 0, result = 0; str1[j] != 0 && result != 1; j++)
		{
			if(str2[i] == str1[j])
			{
				temp[k] = str2[i];
				k++;
				result = 1;
			}
		}
	}
	
	temp[k] = 0;
	
	for(i = 0; temp[i] != 0; i++)
	{
		str2[i] = temp[i];
	}
	
	for(i = 0; i < 1023; i++, temp[i] = 0)
	{ }
	
	
	for(i = 0, j = 0; str1[i] != 0; i++)
	{
		for(result = 0; str2[j] != 0 && result != 1; j++)
		{
			if(str1[i] == str2[j])
			{
				temp[res1] = str1[i];
				res1++;
				result = 1;
			}
		}
	}
	
	
	for(i = 0, j = 0; str2[i] != 0; i++)
	{
		for(result = 0; str1[j] != 0 && result != 1; j++)
		{
			if(str2[i] == str1[j])
			{
				temp2[res2] = str2[i];
				res2++;
				result = 1;
			}
		}
	}
	
	temp2[res2];
	
	if(res1 > res2)
	{
		printf("%i\n", res1);
		fputs(temp, oup);
	}
	else
	{
		printf("%i\n", res2);
		fputs(temp2, oup);
	}
	
	for(i = 0; i < 1023; i++, temp[i] = 0)
	{ }
	
	
	return;
}
	

int main(int argc, char **argv)
{
	int i, result = 0;
	
	if(argc != 4)
	{
		printf("USAGE: <%s> <file1> <file2> <outputfile>\n", argv[0]);
		return -1;
	}
	
	inp1 = fopen(argv[1], "r");
	inp2 = fopen(argv[2], "r");
	oup = fopen(argv[3], "w+");
	
	if(inp1 == NULL) {
		printf("---MAJOR PHAILURE---\nFile %s could not be opened for reading! *dying*\n", argv[1]);
		return -1;
	}
	
	if(inp2 == NULL) {
		printf("---MAJOR PHAILURE---\nFile %s could not be opened for reading! *dying*\n", argv[2]);
		return -1;
	}
	
	if(oup == NULL) {
		printf("---MAJOR PHAILURE---\nFile %s could not be opened for write+trunc *dying*\n", argv[3]);
		return -1;
	}
	
	printf("OK, now we have all the files...\n");
	
	for(i = 0; result != -1; i++)
	{
		fgets(str1, 1000, inp1);
		fgets(str2, 1000, inp2);
		if(!feof(inp1))
		{
			if(!feof(inp2))
			{
				strip();
			}
		}
		else
		{
			result = -1;
		}
		if(result == -1)
		{
			printf("Found EOF, stopping... (Well, duh!)\n");
			result = -1;
		}
	}
		
	return 0;
}