correctly label euler solutions

examples/puzzles/euler_04.zr

@@ -1,22 +1,13 @@
-func collatz_num[n: i64] : i64
-    if n % 2 == 0
-        return n / 2
-    return n * 3 + 1
-
-func collatz_seq[n: i64]: i64
-    let i: i64 = 1
-    while n != 1
-        n = collatz_num(n)
-        i = i + 1
-    return i
-
 func main[] : i64
-    let max: i64 = 0
-    let max_index: i64 = 0
+    let out: i64 = 0
 
-    for i in 1..1000000
-        let seq: i64 = collatz_seq(i)
-        if seq > max
-            max = seq
-            max_index = i
-    io.println_i64(max_index)
+    for a in 500..1000
+        for b in 500..1000
+            if a * b > out
+                let s: str = str.from_i64(a * b)
+                let s_rev: str = str.reverse(s)
+                if str.equal(s, s_rev)
+                    out = a * b
+                mem.free(s)
+                mem.free(s_rev)
+    io.println_i64(out)