diff --git a/2023/day19.py b/2023/day19.py
new file mode 100755
index 0000000..2f332b6
--- /dev/null
+++ b/2023/day19.py
@@ -0,0 +1,135 @@
+#!/usr/bin/python3
+"""
+Jour 19 du défi Advent Of Code pour l'année 2023
+"""
+import os
+
+def read_sample():
+    """récupère les entrées depuis le fichier texte correspondant"""
+    filename = os.path.join(os.path.dirname(__file__ ), "inputs", "day19.txt")
+    with open(filename, 'r') as f:
+        sample = f.read()
+    return sample
+
+def parse_sample(sample):
+    def parse_wf(wf):
+        name = wf.split("{")[0]
+        content = wf.split("{")[1].split("}")[0].split(",")
+        return name, content
+
+    def parse_part(part):
+        content = part.split("{")[1].split("}")[0].split(",")
+        dico = {p.split("=")[0]: int(p.split("=")[1]) for p in content}
+        return dico
+
+    workflows, parts, = sample.split("\n\n")
+    workflows = [parse_wf(i) for i in workflows.split("\n") if i != '']
+    workflows = {i[0]: i[1] for i in workflows}
+    parts = [parse_part(i) for i in parts.split("\n") if i != '']
+    return workflows, parts
+
+
+def process(part, workflows, start="in"):
+    def goto(instr):
+        if instr == "A":
+            return True
+        if instr == "R":
+            return False
+        return process(part, workflows, start=instr)
+
+    def ceval(expr):
+        if '>' in expr:
+            a, b, = expr.split('>')
+            return part[a] > int(b)
+        if '<' in expr:
+            a, b, = expr.split('<')
+            return part[a] < int(b)
+
+    for instr in workflows[start]:
+        if ':' in instr:
+            if ceval(instr.split(":")[0]):
+                return goto(instr.split(":")[1])
+        else:
+            return goto(instr)
+    return goto("R")
+
+
+def process2(part, workflows, start="in"):
+    def sizeof(part):
+        prod = 1
+        for i in part.values():
+            prod *= i[1]-i[0]+1
+        return prod
+
+    def goto(instr, part):
+        if instr == "A":
+            return sizeof(part) # taille de l'instance
+        if instr == "R":
+            return 0
+        return process2(part, workflows, start=instr)
+
+    def apply_flows(part, flows):
+        if not flows:
+            raise NotImplementedError
+        instr, *next_flows = flows
+
+        if ":" not in instr:
+            return goto(instr, part)
+
+        expr = instr.split(":")[0]
+        action = instr.split(":")[1]
+        if '>' in expr:
+            a, b, = expr.split('>')
+            if part[a][0] > int(b):
+                return goto(action, part)
+            if part[a][1] <= int(b):
+                return apply_flows(part, next_flows)
+
+            left = part.copy()
+            right = part.copy()
+            left[a] = (part[a][0], int(b))
+            right[a] = (int(b)+1, part[a][1])
+            return goto(action, right)+apply_flows(left, next_flows)
+        
+        if '<' in expr:
+            a, b, = expr.split('<')
+            if part[a][1] < int(b):
+                return goto(action, part)
+            if part[a][0] >= int(b):
+                return apply_flows(part, next_flows)
+
+            left = part.copy()
+            right = part.copy()
+            left[a] = (part[a][0], int(b)-1)
+            right[a] = (int(b), part[a][1])
+            return goto(action, left)+apply_flows(right, next_flows)
+
+    return apply_flows(part, workflows[start])
+            
+
+
+def part1(sample):
+    """Partie 1 du défi"""
+    workflows, parts = parse_sample(sample)
+    somme = 0
+    for part in parts:
+        if process(part, workflows):
+            somme += part["x"]+part["m"]+part["a"]+part["s"]
+    return somme
+
+
+def part2(sample):
+    """Partie 2 du défi"""
+    workflows, _ = parse_sample(sample)
+
+    return process2({"x":(1, 4000), "m":(1, 4000), "a":(1, 4000), "s":(1, 4000)}, workflows)
+
+
+def main():
+    """Fonction principale"""
+    sample = read_sample()
+    print(f"part1: {part1(sample)}")
+    print(f"part2: {part2(sample)}")
+
+if __name__ == "__main__":
+    main()
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