N = int(input())
sm = 0
for i in range(N):
    s = input()
    if '.' in s:
        id = s.index('.')
        # print(int(s[:id]+s[id+1:]+'0'*(10-len(s[id+1:]))))
        sm += int(s[:id]+s[id+1:]+'0'*(10-len(s[id+1:])))
    else:
        # print(int(s+'0'*10))
        sm += int(s+'0'*10)
print(str(sm)[:-10]+'.'+str(sm)[-10:])