diff --git a/day5/p1.c b/day5/p1.c
index 82918ba..d458ac8 100644
--- a/day5/p1.c
+++ b/day5/p1.c
@@ -6,9 +6,6 @@
 #include <stdbool.h>
 
 
-#define ABS(n) ((n < 0) ? n * -1 : n)
-
-
 int64_t parse_number(char *end);
 
 
@@ -20,12 +17,10 @@ int main(int argc, char **argv) {
     if (argc == 1 || argv[1][0] == '-')
 		input = stdin;
 	else if ((input = fopen(argv[1], "r")) == NULL) {
-		printf("Cannot open file %s\n", argv[1]);
+		fprintf(stderr, "Cannot open file %s\n", argv[1]);
 		return -1;
 	}
 
-    int64_t *data = NULL;
-
     getline(&line, &line_buf_length, input);
 
     char *colon_pos = strchr(line, ':');
@@ -36,8 +31,7 @@ int main(int argc, char **argv) {
         space_pos++;
     }
 
-    data = (int64_t *) calloc(data_len, sizeof(int64_t));
-
+    int64_t *data = (int64_t *) calloc(data_len, sizeof(int64_t));
     bool *data_v = (bool *) calloc(data_len, sizeof(bool));
 
     for (size_t i = 0, seeds_pos = (size_t) colon_pos+2;; seeds_pos++) {
@@ -59,7 +53,7 @@ int main(int argc, char **argv) {
 
         for (size_t i = 0; i < data_len; ++i) {
             if (!data_v[i] && data[i] >= src && data[i] <= src+rng-1) {
-                data[i] = dst + ABS(data[i] - src);
+                data[i] = dst + (data[i] - src);
                 data_v[i] = true;
             }
         }
@@ -69,9 +63,8 @@ int main(int argc, char **argv) {
 
     int64_t lowest_loc_n = INT32_MAX;
 
-    for (size_t i = 0; i < data_len; ++i) {
+    for (size_t i = 0; i < data_len; ++i)
         lowest_loc_n = (data[i] < lowest_loc_n) ? data[i] : lowest_loc_n;
-    }
 
     printf("%ld\n", lowest_loc_n);
 
@@ -81,10 +74,10 @@ int main(int argc, char **argv) {
 int64_t parse_number(char *end) {
     int64_t num = 0;
 
-    for (size_t n = 1;; n *= 10) {
+    for (size_t m = 1;; m *= 10) {
         if (*end>>4 != 0x3)
             break;
-        num += (*end&0xf) * n;
+        num += (*end&0xf) * m;
         --end;
     }