n=int(input())
res0,res1=0,0
for _ in range(n):
  x=input()
  if '.' in x:
    c0,c1=x.split('.')
    res0+=int(c0)
    res1+=int(c1+'0'*(10-len(c1)))
    
  else:
    res0+=int(x)

res0+=res1//(10**10)
res1%=10**10
res1=str(res1)
ans=str(res0)+'.'+'0'*(10-len(res1))+res1
print(ans)