letters = 'abcdefghijklmnopqrstuvwxyz;
freq = 0.01 * [8.167 	
 
	1.492 	
 
 	2.782 	
 
 	4.253 	
 
 	12.702 	
 
 	2.228 	
 
 	2.015 	
 
 	6.094 	
 
 	6.966 	
 
 	0.153 	
 
 	0.772 	
 
 	4.025 	
 
 	2.406 	
 
 	6.749 	
 
 	7.507 	
 
 	1.929 	
 
 	0.095 	
 
 	5.987 	
 
 	6.327 	
 
 	9.056 	
 
 	2.758 	
 
 	0.978 	
 
 	2.360 	
 
 	0.150 	
 
 	1.974 	
 
 	0.074];