R Program to multiply two numbers

Program

a <- readline(prompt = "Enter first number:")
a <- as.integer(a)
b <- readline(prompt = "Enter second number:")
b <- as.integer(b)
difference = a - b
print(paste("Difference of two numbers is: ", difference))

Output

> a <- readline(prompt = "Enter first number:")
Enter first number:87
> a <- as.integer(a)
> b <- readline(prompt = "Enter second number:")
Enter second number:165
> b <- as.integer(b)
> difference = a - b
> print(paste("Difference of two numbers is: ", difference))
[1] "Difference of two numbers is:  -78"