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

int32_t compint(const void *a, const void *b) {
	uint16_t tmp_a = *((uint16_t *)a);
	uint16_t tmp_b = *((uint16_t *)b);

	if (tmp_a == tmp_b) return 0;
	else if (tmp_a > tmp_b) return 1;
	else return -1;
}

int main() {
	FILE *file = fopen("input", "r");
	if (file == NULL) {
		perror("main: Error opening file.");
		return 1;
	}

	uint16_t l, w, h, sa_tmp;
	uint32_t sa_cum = 0;
	int8_t buffer[256];
	while (fgets(buffer, sizeof(buffer), file) != NULL) {
		if (sscanf(buffer, "%hux%hux%hu", &l, &w, &h) != 3) {
			perror("main: Error parsing string.");
			return 1;
		}
		else {
			//calculate surface area
			sa_tmp = 2*l*w + 2*w*h + 2*l*h;

			//calculate smallest side
			uint16_t array[3] = {l, w, h};
			uint16_t n = sizeof(array)/sizeof(array[0]);
			qsort(array, n, sizeof(array[0]), compint);

			//calculate cumulative surface area
			sa_cum = sa_cum + sa_tmp + (array[0]*array[1]);
		}
	}
	if (ferror(file)) {
		perror("main: Error reading from file.");
		return 1;
	}
	fclose(file);

	printf("cumulative surface area: %u\n", sa_cum);

	return 0;
}