# this is a simple probabilistic program without loops.
# 3, 5, and 7 resource units are consumed with the same probability 1/3.
# Thus the expected resource usage is 1/3*3 + 1/3*5 + 1/3*7 = 5

def f():
    var flag, z

    prob(1,2):
        flag = 0
        tick 3
    else:
        prob(1,1):
            flag = 1
            tick 5
        else:
            flag = 1
            tick 7