diff --git a/results/b2/parse.c b/results/parse.c
similarity index 87%
rename from results/b2/parse.c
rename to results/parse.c
index a27a92b..6476928 100644
--- a/results/b2/parse.c
+++ b/results/parse.c
@@ -1,3 +1,8 @@
+/**
+ * Compile: cc -O2 -luuid parse.c -o parse
+ * Usage: ./parse 7500 a.bin b.bin
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
@@ -11,18 +16,24 @@ int cmpuint64t(const void* u1, const void* u2) {
 }
 
 int main(int argc, char *argv[]) {
+  if (argc < 3) {
+    printf("Usage: %s <count> <filepath>+\n", argv[0]);
+    exit(EXIT_FAILURE);
+  }
+
   FILE *r, *w;
   uint64_t taglen;
-  char tag[255];
+  char tag[255], filename[255];
   uuid_t uuid;
   char uuidstr[37];
   uint64_t meascount;
   uint64_t meas[25*60*90]; /* can contain up to ninety minutes of meas */
-  uint64_t target = 25*60*5; /* five minutes of measures*/
+  uint64_t target = atoi(argv[1]); /* subset of measures to consider */
 
-  if ((w = fopen("5min.csv", "w")) == NULL) goto iofail;
+  sprintf(filename, "%d.csv", target);
+  if ((w = fopen(filename, "w")) == NULL) goto iofail;
 
-  for (int i = 1; i < argc; i++) {
+  for (int i = 2; i < argc; i++) {
     printf("selected %s\n", argv[i]);
     if ((r = fopen(argv[i], "r")) == NULL) goto iofail;
     if (fread(&taglen, sizeof(taglen), 1, r) != 1) goto iofail;