diff --git a/Makefile b/Makefile
index ccd3933..6eabcaf 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,7 @@ LDFLAGS = -pthread
 
 GFALIBS_DIR := $(CURDIR)/gfalibs
 
-OBJS := main teloscope input 
+OBJS := main teloscope input tools
 BINS := $(addprefix $(BINDIR)/, $(OBJS))
 
 head: $(BINS) gfalibs | $(BUILD)
diff --git a/include/functions.h b/include/functions.h
deleted file mode 100644
index 2dfbd82..0000000
--- a/include/functions.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef FUNCTIONS_H
-#define FUNCTIONS_H
-
-#include <vector>
-#include <string>
-
-void generate_combinations(const std::string &pattern, std::string &current, size_t index, std::vector<std::string> &combinations);
-
-#endif // FUNCTIONS_H
diff --git a/include/main.h b/include/main.h
index 0a6575a..8d20bee 100644
--- a/include/main.h
+++ b/include/main.h
@@ -47,6 +47,6 @@
 #include "input-gfa.h"
 
 #include "input.h" // was in Mac's code
-#include "functions.h"
+#include "tools.h"
 
 #endif /* MAIN_H */
diff --git a/src/functions.cpp b/src/functions.cpp
deleted file mode 100644
index 7c6c578..0000000
--- a/src/functions.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-#include "functions.h"
-#include <unordered_map>
-
-std::unordered_map<char, std::vector<char>> IUPAC_DNA_map = {
-    {'A', {'A'}},
-    {'C', {'C'}},
-    {'G', {'G'}},
-    {'T', {'T'}},
-    {'R', {'A', 'G'}},
-    {'Y', {'C', 'T'}},
-    {'M', {'A', 'C'}},
-    {'K', {'G', 'T'}},
-    {'S', {'C', 'G'}},
-    {'W', {'A', 'T'}},
-    {'H', {'A', 'C', 'T'}},
-    {'B', {'C', 'G', 'T'}},
-    {'V', {'A', 'C', 'G'}},
-    {'D', {'A', 'G', 'T'}},
-    {'N', {'A', 'C', 'G', 'T'}}
-};
-
-
-void generate_combinations(const std::string &pattern, std::string &current, size_t index, std::vector<std::string> &combinations) {
-    if (index == pattern.size()) {
-        combinations.push_back(current);
-        return;
-    }
-
-    char base = pattern[index];
-    for (char c : IUPAC_DNA_map[base]) {
-        current[index] = c;
-        generate_combinations(pattern, current, index + 1, combinations);
-    }
-}
-
-
diff --git a/src/main.cpp b/src/main.cpp
index 313a52b..2badc31 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -241,7 +241,7 @@ int main(int argc, char **argv) {
                 printf("/// Teloscope v%s\n", version.c_str());
 
                 if (userInput.step > userInput.windowSize) {
-                    fprintf(stderr, "Error: Step size (%d) larger than window size (%d) is not allowed.\n", userInput.step, userInput.windowSize);
+                    fprintf(stderr, "Error: Step size (%d) cannot be larger than window size (%d)!\n", userInput.step, userInput.windowSize);
                     exit(EXIT_FAILURE);
 
                 } else if (userInput.step == userInput.windowSize) {
@@ -355,5 +355,4 @@ int main(int argc, char **argv) {
 
     exit(EXIT_SUCCESS);
     
-}
-
+}
\ No newline at end of file