How to make expect command in expect program script to wait for exact string matching

I want to know how to make expect command in expect script to wait for exact string to be matched before proceeding to next line in the script.

The code is as shown below

#!/bin/sh
 #!/usr/bin/expect
 
 spawn ssh -Y localuser@lbblr-tirumala
 expect -exact "localuser@lbblr-tirumala's password: "
 
 # replace password with ur own passwd
 send "geomax45\r"
 
 # replace the prompt with ur own prompt
 expect "localuser@lbblr-tirumala:~$ "
 
 # run application
 send "./sample\r"
 
 expect "*Menu*\r
 1. print hello world\r
 2. print Bye world\r
 3. quit\r
 enter choice: "
 # enter choice 1
 send "1\r"
 expect "Bye world\r
 *Menu*\r
 1. print hello world\r
 2. print Bye world\r
 3. quit\r
 enter choice: $"
 # enter choice 2
 send "2\r"
 

In the above code after entering 1 the code should wait for "Bye world\r......" string to occur on the screen. But even though the screen prompts different string altogether, the code is executing the mext line and entering option 2, which should not occur as per definition of expect. It should wait untill the complete string in expect command matches.

I want to know whether there is any stricter command that can be used so that expect waits until exact string matching occurs. Please help me in this issue

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