strcount={}
strin =input()
for i in strin:
if strcount.get(i):
strcount[i]+=1
else:
strcount[i]=0
strcount=sorted(strcount.items(),key=lambda x:x[1])
for k,v in strcount:
if k!=strcount[0][0]:
print()
print(f"\r{k}:{v}",end='')