Sum of Raju and Ravi age is 1 less than Ramu. After one year, the sum of Raju and Ravi is equal to Ramu's age. After another year, the sum of Raju and Ravi is one more than Ramu's age. If the sum of Raju, Ravi, and Ramu's age is 23. Then what is the age of Ramu?