[uva] Add Python3 solution for 623 - 500!.

Author: abeaumont

uva/00623-1.ans

@@ -0,0 +1,8 @@
+10!
+3628800
+30!
+265252859812191058636308480000000
+50!
+30414093201713378043612608166064768844377641568960512000000000000
+100!
+93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000

uva/00623-1.in

@@ -0,0 +1,4 @@
+10
+30
+50
+100

uva/00623.py

@@ -0,0 +1,10 @@
+#!/usr/bin/env python3
+# https://uva.onlinejudge.org/external/6/623.pdf
+while True:
+    try:
+        n=int(input())
+        print(str(n)+'!')
+        k=1
+        for i in range(1,n+1):k*=i
+        print(k)
+    except:break

uva/README.md

@@ -25,6 +25,8 @@ There are solutions for the following
   ([problem site](https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&category=6&problem=400))
 * [579 - Clock Hands](00579.cc)
   ([problem site](http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=520))
+* [623 - 500!](00623.py)
+  ([problem site](http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=564))
 * [793 - Network Connections](00793.cc)
   ([problem site](http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=734))
 * [10004 - Bicoloring](10004.cc)