4. This question tested nested for loops Write a function called plot(s) in which s is a string representing a social security number written as contiguous digits (for instance, 509435456). It then prints each digit on a separate line followed by a colon and the digit printed the number of times equal to its value. Thus the output for 509435456 would be 5:55555 . 9:999999999 4:4444 3:333 5:55555 4:4444 5:55555 6:666666 4