def checkpanag(str):
	                            l=[]
	                for i in range(26):
		                 l.append(False)
	                  for s in str.lower():
		               if s!=' ':
	                        		l[ord(s)-ord('a')]=True
                 	for c in l:
	                        	if c==False:
	                		return False
	                       return True
  
                  def main():
             	s=input()
	                print(checkpanag(s))
             try:
	                main()
               except:
	                    print('invalid')
