from queue import LifoQueue
def calculate_rpn(rpn: str) -> float:
rpn_stack = LifoQueue()
for symbol in rpn:
if symbol.isdigit():
rpn_stack.put(int(symbol))
else:
b, a = rpn_stack.get(), rpn_stack.get()
result = eval(f"{a} {symbol} {b}")
rpn_stack.put(result)
return rpn_stack.get()
rpn = "27+3/13-4*+2/"
result = calculate_rpn(rpn)
print(result)