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+## Remarks
+## https://www.geeksforgeeks.org/program-mobius-function/
+
+## Python program to evaluate
+## Mobius def M(N) = 1 if N = 1
+## M(N) = 0 if any prime factor of N is contained twice
+## M(N) = (-1) ^ (no of distinct prime factors)
+
+
+import math
+
+
+## def to check if n is prime or not
+def isPrime(n) :
+
+    if (n < 2) :
+        return False
+
+    for i in range(2, n + 1) :
+        if (n % i == 0) :
+            return False
+ 
+        i = i * i
+ 
+    return True
+
+
+def mobius(n) :
+
+    p = 0
+
+	## Handling 2 separately
+    if (n % 2 == 0) :
+
+        n = int(n / 2)
+        p = p + 1
+
+        ## If 2^2 also divides N
+        if (n % 2 == 0) :
+            return 0
+
+    ## Check for all other prime factors
+    for i in range(3, int(math.sqrt(n)) + 1) :
+
+        ## If i divides n
+        if (n % i == 0) :
+
+            n = int(n / i)
+            p = p + 1
+
+            ## If i ^ 2 also divides N
+            if (n % i == 0) :
+                return 0
+
+        i = i + 2
+
+    if(p % 2 == 0) :
+        return -1
+
+    return 1
+
+## Driver Code
+## N = 5 ## Example: 1
+## N = 10 ## Example: 2
+N = 20 ## Example: 3
+
+print ("Mobius defs M(N) at N = {} is: {}\n" . format(N, mobius(N)));
+
+							
+## This code is contributed by Manish Shaw (manishshaw1)