def can_complete_circuit(gas, cost):
    if sum(gas) < sum(cost):
        return -1
    start = 0
    bal = 0
    for i in range(len(gas)):
        bal += gas[i] - cost[i]
        if bal < 0:
            start = i + 1
            bal = 0
    return start


if __name__ == "__main__":
    print(can_complete_circuit([1, 2, 3, 4, 5], [3, 4, 5, 1, 2]))
    print(can_complete_circuit([2, 3, 4], [3, 4, 3]))