Multiply and quadrature the numbers in the list in Python

The phenomenon and background of the problem

Problem related code , Do not paste screenshots

ls=[111,222,333,444,555,666,777,888,999]
lt=[999,777,555,333,111]

Operation results and error reporting contents

My solution ideas and tried methods

What I want to achieve

The final result should be ：111999+222777+333555+444333+555*111+666+777+888+999 And

cnt = 0for i in range (len(ls)):if i ＜len(lt):cnt += int(str(ls[i]) + str(lt[i]))else:cnt += ls[i]print(cnt)

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