diff --git a/5_lcm.py b/5_lcm.py
new file mode 100644
index 0000000..649f379
--- /dev/null
+++ b/5_lcm.py
@@ -0,0 +1,12 @@
+def gcd(a,b):
+    while b:
+        a,b=b,a%b
+    return a
+
+def lcm(a,b):
+    return (a*b)//gcd(a,b)
+    
+x=1
+for i in range(2,21):
+    x=lcm(x,i)
+print(x)