diff --git a/lib/libflint b/lib/libflint
index 92a787a..80ce772 160000
--- a/lib/libflint
+++ b/lib/libflint
@@ -1 +1 @@
-Subproject commit 92a787a899621aa0290ef746035596ad3485c70e
+Subproject commit 80ce772c9c9ae5e459c0c10e1fae20738ca2f949
diff --git a/src/2023/01.c b/src/2023/01.c
index 36382ba..f2f7eb2 100644
--- a/src/2023/01.c
+++ b/src/2023/01.c
@@ -1,13 +1,97 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
 
 #include "lfinput.h"
+#include "lfstring.h"
+
+static int part_one(char **lines, size_t sz) {
+    int p1 = 0;
+    int first = 0, last = 0;
+
+    for (size_t i = 0; i < sz; ++i) {
+        for (size_t j = 0; j < strlen(lines[i]); ++j) {
+            if (isdigit(lines[i][j])) {
+                first = lines[i][j] - '0';
+                break;
+            }
+        }
+
+        for (int j = (int)strlen(lines[i]) - 1; j >= 0; --j) {
+            if (isdigit(lines[i][j])) {
+                last = lines[i][j] - '0';
+                p1 += first * 10 + last;
+                break;
+            }
+        }
+    }
+
+    return p1;
+}
+
+#define numwords_sz 9
+
+static char *numwords[numwords_sz] = {
+        "one",
+        "two",
+        "three",
+        "four",
+        "five",
+        "six",
+        "seven",
+        "eight",
+        "nine"
+};
+
+static int part_two(char **lines, size_t sz) {
+    int p2 = 0;
+    int first = 0, last = 0;
+
+    for (size_t i = 0; i < sz; ++i) {
+        for (size_t j = 0; j < strlen(lines[i]); ++j) {
+            if (isdigit(lines[i][j])) {
+                first = lines[i][j] - '0';
+                goto LAST_LOOP;
+            }
+            for (size_t k = 0; k < numwords_sz; ++k) {
+                const char *s = substr(lines[i], j, strlen(numwords[k]));
+                if (s != NULL && strcmp(s, numwords[k]) == 0) {
+                    first = (int)k + 1;
+                    free(s);
+                    goto LAST_LOOP;
+                }
+                free(s);
+            }
+        }
+
+        LAST_LOOP:
+        for (int j = (int)strlen(lines[i]) - 1; j >= 0; --j) {
+            if (isdigit(lines[i][j])) {
+                last = lines[i][j] - '0';
+                goto NEXT_LINE;
+            }
+            for (size_t k = 0; k < numwords_sz; ++k) {
+                const char *s = substr(lines[i], j, strlen(numwords[k]));
+                if (s != NULL && strcmp(s, numwords[k]) == 0) {
+                    last = (int)k + 1;
+                    free(s);
+                    goto NEXT_LINE;
+                }
+                free(s);
+            }
+        }
+
+        NEXT_LINE:
+        p2 += first * 10 + last;
+    }
+
+    return p2;
+}
 
 void advent2023day01(void) {
     size_t sz = 0;
     char **lines = get_lines("input/2023/01", &sz);
-
-
-
+    printf("%d\n%d\n", part_one(lines, sz), part_two(lines, sz));
     del_lines(lines);
 }