Write a program to find the value of a postfix expression.

Write a program to find the value of a postfix expression. Variables are one or more characters each. We might have some integer numbers as part of the expression. $($Hint$.$ Read each part of

the expression as a token of type string, if the first character of the token is a letter that indicates the

token is a variable name, push its value in stack. If the token is an integer number use the predefined

function stoi $($member of Sample $1/$O:

Enter a postfix expression with a $ at the end: $20$ jerry $45+$ tom $-*$$

Enter the value of jerry: $10$

Enter the value of tom: $5$

Expression's value is $1000$

CONTINUE$($y$/$n$)?$ y

Enter a postfix expression with a $ at the end: myscore yourscore $45+100+{?}^{**}$$

Enter the value of myscore: $3$

Enter the value of yourscore: $5$

Expressions value is $450$

CONTINUE $(\frac{y}{n})?n$

As input, please use the given expressions and the given values.