syntax error help - beginner level

this is a code I'm writing for a small assignment. when I run the code in command prompt it is not asking me to input anything but it's showing a syntax error in line 8

import math
t = 0  
h = 1000
u = 0
f = 1000
while h > 0:
    burnt_fuel = input("Enter fuel to burn in the next second")
    if burnt_fuel >= 0:
        h = h - (u - 0.5*(1.6-(burnt_fuel*0.15))
        t = t + 1
        u = u + a
        f = f - burnt_fuel