diff --git a/c-gaps/credit.c b/c-gaps/credit.c
index 2a60e39..aff4476 100644
--- a/c-gaps/credit.c
+++ b/c-gaps/credit.c
@@ -1,9 +1,72 @@
 #include <lua.h>
 #include <lauxlib.h>
+#include <stdlib.h>
 
-// implement it here
+int removeGaps(lua_State* L) {
+	luaL_argcheck(L, lua_type(L, 1) == LUA_TTABLE, 1, "Please, input table");
+
+	size_t table_len = lua_objlen(L, -1);
+
+	if (table_len == 0) {
+		lua_newtable(L);
+		return 1;
+	}
+
+	const char** table = malloc(sizeof(char*) * table_len);
+	char** new_table = malloc(sizeof(char*) * table_len);
+
+	size_t len;
+	lua_rawgeti(L, 1, 1);
+	table[0] = luaL_checklstring(L, -1, &len);
+	luaL_argcheck(L, lua_type(L, -1) == LUA_TSTRING, -1, "Table members should be strings");
+	lua_pop(L, 1);
+
+	int i = 0;
+	int j = 0;
+	int k = 0;
+
+	for (i = 0; i < table_len; i++) {
+		new_table[i] = malloc(sizeof(char) * len);
+	}
+
+	for (i = 2; i <= table_len; i++) {
+		size_t local_len;
+		lua_rawgeti(L, 1, i);
+		table[i - 1] = luaL_checklstring(L, -1, &local_len);
+		luaL_argcheck(L, local_len == len, -1, "Strings should have equal length");
+		lua_pop(L, 1);
+	}
+
+	for (j = 0; j < len; j++) {
+		char gap_column = "smth";
+		for (i = 0; i < table_len; i++) {
+			if (table[i][j] != '-') {
+				gap_column = NULL;
+			}
+		}
+		if (! gap_column) {
+			for (i = 0; i < table_len; i++) {
+				new_table[i][k] = table[i][j];
+			}
+			k = k + 1;
+		}
+	}
+
+	lua_newtable(L);
+	for (i = 0; i < table_len; i++) {
+		lua_pushlstring(L, new_table[i], k);
+		lua_rawseti(L, -2, i + 1);
+	}
+
+	for (i = 0; i < table_len; i++) {
+		free(new_table[i]);
+	}
+	free(table);
+	free(new_table);
+	return 1;
+}
 
 int luaopen_gaps(lua_State* L) {
-    // return it here
-    return 0;
+	lua_pushcfunction(L, removeGaps);
+	return 1;
 }
diff --git a/c-gaps/spec.lua b/c-gaps/spec.lua
index 2129000..498c005 100644
--- a/c-gaps/spec.lua
+++ b/c-gaps/spec.lua
@@ -1,9 +1,9 @@
 describe("gaps (implementation)", function()
-    pending("loads module", function()
+    it("loads module", function()
         local f = require 'gaps'
     end)
 
-    pending("doesn't change good alignment", function()
+    it("doesn't change good alignment", function()
         local f = require 'gaps'
         assert.same({}, f({}))
         assert.same({''}, f({''}))
@@ -14,7 +14,7 @@ describe("gaps (implementation)", function()
         assert.same({'A'}, f({'A-'}))
     end)
 
-    pending("removes gap columns", function()
+    it("removes gap columns", function()
         local f = require 'gaps'
         assert.same({''}, f({'-'}))
         assert.same({'', ''}, f({'-', '-'}))
@@ -30,7 +30,7 @@ describe("gaps (implementation)", function()
         }))
     end)
 
-    pending("throws error if input is not table",
+    it("throws error if input is not table",
     function()
         local f = require 'gaps'
         assert.has_error(function()
@@ -41,7 +41,7 @@ describe("gaps (implementation)", function()
         end)
     end)
 
-    pending("throws error if table members are not strings",
+    it("throws error if table members are not strings",
     function()
         local f = require 'gaps'
         assert.has_error(function()
@@ -49,7 +49,7 @@ describe("gaps (implementation)", function()
         end)
     end)
 
-    pending("throws error if strings' lengths differ",
+    it("throws error if strings' lengths differ",
     function()
         local f = require 'gaps'
         assert.has_error(function()