# your code goes here
a = ['<a1>', '<a2>', '<a3>', '', '<a5>']
b = ['<b1>', '<b2>', '<b3>', '', '<b5>']
txt = '<a1> test <a2> test <a3> test <a4> test <a5>'
for idx, val in enumerate(a):
txt = txt.replace(val, b[idx])
print(txt)
IyB5b3VyIGNvZGUgZ29lcyBoZXJlCgphID0gWyc8YTE+JywgJzxhMj4nLCAnPGEzPicsICcnLCAnPGE1PiddCmIgPSBbJzxiMT4nLCAnPGIyPicsICc8YjM+JywgJycsICc8YjU+J10KdHh0ID0gJzxhMT4gdGVzdCA8YTI+IHRlc3QgPGEzPiB0ZXN0IDxhND4gdGVzdCA8YTU+JwoKZm9yIGlkeCwgdmFsIGluIGVudW1lcmF0ZShhKToKICAgIHR4dCA9IHR4dC5yZXBsYWNlKHZhbCwgYltpZHhdKQoKcHJpbnQodHh0KQ==