Index: aoc.c
==================================================================
--- aoc.c
+++ aoc.c
@@ -5,11 +5,11 @@
 #include <stdlib.h>
 #include <string.h>
 #include "aocdailies.h" // prototypes for all aocYYYYdd functions!
 #include "aocutils.h"
 
-#define MAX_YEAR 2024
+#define MAX_YEAR 2025
 
 int main(int argc, char **argv) {
     unsigned y = 0, d = 0;
     char dataname[99];
     if (argc >= 3) {

Index: aocdailies.c
==================================================================
--- aocdailies.c
+++ aocdailies.c
@@ -3,10 +3,14 @@
 
 aocfunc *aocselect(unsigned y, unsigned d) {
     aocfunc *p;
     switch (y * 100 + d) {
         default: p = NULL; break;
+
+        case 202503: p = aoc202503; break;
+        case 202502: p = aoc202502; break;
+        case 202501: p = aoc202501; break;
 
         //   YYYYdd ==>  aocYYYYdd
         case 202422: p = aoc202422; break;
         case 202417: p = aoc202417; break;
         case 202409: p = aoc202409; break;

Index: aocdailies.h
==================================================================
--- aocdailies.h
+++ aocdailies.h
@@ -3,10 +3,14 @@
 
 #include <stddef.h>
 
 typedef void aocfunc(char *, size_t);
 aocfunc *aocselect(unsigned, unsigned);
+
+aocfunc aoc202503;
+aocfunc aoc202502;
+aocfunc aoc202501;
 
 aocfunc aoc202422;
 aocfunc aoc202417;
 aocfunc aoc202409;
 aocfunc aoc202408;

Index: aocutils.c
==================================================================
--- aocutils.c
+++ aocutils.c
@@ -33,10 +33,16 @@
     tmp += F(b, c, d);
     tmp += k;
     tmp += t;
     *a = b + rotateleft(tmp, s);
 }
+
+long long unsigned upow(unsigned base, unsigned exponent) {
+    long long unsigned result = 1;
+    while (exponent--) result *= base;
+    return result;
+}
 
 void md5mini(unsigned char *dstarr, const char *src) {
     // see https://www.ietf.org/rfc/rfc1321.txt
     static uint32_t T[64] = {0};
     if (T[0] == 0) {

Index: aocutils.h
==================================================================
--- aocutils.h
+++ aocutils.h
@@ -5,10 +5,12 @@
 
 struct TextGrid {
     unsigned cols, rows;
     char *data; // may have '\n' at end of rows
 };
+
+long long unsigned upow(unsigned base, unsigned exponent);
 
 void md5mini(unsigned char *dstarr, const char *src);
 
 bool TGvalid(struct TextGrid *tg, unsigned col, unsigned row);
 char *TGcharptr(struct TextGrid *tg, unsigned col, unsigned row);