s = input()
st = [0]* 1000
top = -1
s = s.split()
temp = 0

for i in range(len(s)):
    if s[i] >= '0' and s[i] <= '9':
        top = top + 1
        st[top] = int(s[i])
    
    elif s[i] == '+':
        temp = st[top - 1] + st[top]
        top = top - 1
        st[top] = temp
    
    elif s[i] == '-':
        temp = st[top - 1] - st[top]
        top = top - 1
        st[top] = temp
    
    elif s[i] == '*':
        temp = st[top - 1]* st[top]
        top = top - 1
        st[top] = temp
    
    elif s[i] == '/':
        temp = st[top - 1]/ st[top]
        top = top - 1
        st[top] = temp
    
print("%.2f" % st[0])