2. The computer program product of claim 1 , wherein the operations further comprise: generating a word frequency distribution of frequencies of occurrences of all of the words; assigning values to different numbers of merged words based on the word frequency distribution; and selecting one of the numbers of the merged words based on the assigned values, wherein the number of symbols comprises the selected number of the merged words, wherein each symbol maps to one of the merged words.
2. The computer program product of claim 1 , wherein the operations further comprise: generating a word frequency distribution of frequencies of occurrences of all of the words; assigning values to different numbers of merged words based on the word frequency distribution; and selecting one of the numbers of the merged words based on the assigned values, wherein the number of symbols comprises the selected number of the merged words, wherein each symbol maps to one of the merged words. 3. The computer program product of claim 2 , wherein the assigned value for each number of the merged words is calculated based on a probability of occurrence of each alphabet code symbol representing.