Given the strings s1 and s2 that are of the same length, create a new string consisting of the first character of s1 followed by the first character of s2, followed by the second character of s1, followed by the second character of s2, and so on (in other words the new string should consist of alternating characters of s1 and s2). For example, if s1 contained "hello" and s2 contained "world", then the new string should contain "helloworld". Associate the new string with the variable s3.