Write a C program which receives two strings: Sl and S2, and an integer I. String S1 is composed of letters (A, B, C, D ...etc) and digits (0 to 9) characters only, while S2 is empty. The function should copy to S2 all the digit characters representing the Ith integer in string S1. Example 1: Example 2: Example 3: Given SI = "abc213fet23djg11dFG4" Given SI = "abc213fe123djg11dFG4" Given SI = "abc213fet23djg11dFG87" If I is equal to 1 If I is equal to 2 If I is equal to 4 The function should copy "213 to S2 The function should copy "23" to S2 The function should copy"87" into S2 Do not use any ready function except strlen(. You have to write your own code In main do the following: 1. Define necessary strings for the function 2. Read a string and an integer number from user. 3. Call the function. 4. Print the result string