Write a program that reads a string and counts the occurrences of each letter. The letters are case$-$insensitive. The program displays the letters and their corresponding count in increasing order of the count. If the two counts are equal, use the alphabetic order. The letters are displayed in lowercase.

Sample Run

Enter a string: Welcome to Java

c: $1$

j: $1$

l: $1$

m: $1$

t: $1$

v: $1$

w: $1$

a: $2$

e: $2$

o: $2$