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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def exp_rmspe(pred:Tensor, targ:Tensor)->Rank0Tensor:
    "Exp RMSE between `pred` and `targ`."
    pred,targ = flatten_check(pred,targ)
    pred, targ = torch.exp(pred), torch.exp(targ)
    pct_var = (targ - pred)/targ
    return torch.sqrt((pct_var**2).mean())