add example

src/largestfactor.py

@@ -0,0 +1,13 @@
+n = int(input())
+factors = []
+d = 2
+while n > 1:
+    while n % d == 0:
+        factors.append(d)
+        n //= d
+    d = d + 1
+    if d * d > n:
+        if n > 1:
+            factors.append(n)
+        break
+print(factors[-1])