Strings Compression

Take as input S, a string. Write a function that does basic string compression. Print the value returned. E.g. for input “aaabbccds” print out a3b2c2d1s1.
Input Format

A single String S
Constraints

1 < = length of String < = 1000
Output Format

The compressed String.
Sample Input

aaabbccds

Sample Output

a3b2c2d1s1

Explanation

In the given sample test case 'a' is repeated 3 times consecutively, 'b' is repeated twice, 'c' is repeated twice and 'd and 's' occurred only once.