Do day 1 and 2.

d1.py

@@ -0,0 +1,64 @@
+import re
+
+EXAMPLE = """
+1000
+2000
+3000
+
+4000
+
+5000
+6000
+
+7000
+8000
+9000
+
+10000
+"""
+
+def solve(lines: list[str]):
+    counter = 0
+    count_max = 0
+    for line in lines.splitlines():
+        if line.strip() == "":
+            if counter >= count_max:
+                count_max = counter
+            counter = 0
+        else:
+            counter += int(line)
+    return count_max
+
+def solve2(lines: list[str]):
+    counter = 0
+    count_max = 0
+    counts = []
+    for line in lines.splitlines():
+        if line.strip() == "":
+            if counter >= count_max:
+                count_max = counter
+            counts.append(counter)
+            counter = 0
+        else:
+            counter += int(line)
+    counts.append(counter)
+
+    counts.sort(reverse=True)
+    return sum(counts[:3])
+
+def main():
+    example = str(EXAMPLE)
+    print("Example  1:", solve(example))
+
+    data = open("i1.txt").read()
+    print("Solution 1:", solve(data))
+
+    example = str(EXAMPLE)
+    print("Example  2:", solve2(example))
+
+    data = open("i1.txt").read()
+    print("Solution 2:", solve2(data))
+    return
+
+if __name__ == "__main__":
+    main()