import re
out = '''
<change://problem/59689726> This is a test1
change://1234567 This is a test2
[Problem]
This is problem desription
'''
m = re.findall("change://(?:problem/)?(\d+)", out.split('[Problem]')[0])
if m:
for radar in set(m):
print (radar)
aW1wb3J0IHJlCm91dCA9ICcnJwo8Y2hhbmdlOi8vcHJvYmxlbS81OTY4OTcyNj4gVGhpcyBpcyBhIHRlc3QxCmNoYW5nZTovLzEyMzQ1NjcgVGhpcyBpcyBhIHRlc3QyCltQcm9ibGVtXQpUaGlzIGlzIHByb2JsZW0gZGVzcmlwdGlvbgonJycKbSA9IHJlLmZpbmRhbGwoImNoYW5nZTovLyg/OnByb2JsZW0vKT8oXGQrKSIsIG91dC5zcGxpdCgnW1Byb2JsZW1dJylbMF0pCmlmIG06CiAgICBmb3IgcmFkYXIgaW4gc2V0KG0pOgogICAgICAgIHByaW50IChyYWRhcik=