Having this error
RuntimeError                              Traceback (most recent call last)
<ipython-input-27-8c2bbe9e4336> in <module>
      1 #Fit the model
----> 2 learn.fit_one_cycle(1,slice(lr))#5

/opt/conda/lib/python3.6/site-packages/fastai/train.py in fit_one_cycle(learn, cyc_len, max_lr, moms, div_factor, pct_start, final_div, wd, callbacks, tot_epochs, start_epoch)
     20     callbacks.append(OneCycleScheduler(learn, max_lr, moms=moms, div_factor=div_factor, pct_start=pct_start,
     21                                        final_div=final_div, tot_epochs=tot_epochs, start_epoch=start_epoch))
---> 22     learn.fit(cyc_len, max_lr, wd=wd, callbacks=callbacks)
     23 
     24 def lr_find(learn:Learner, start_lr:Floats=1e-7, end_lr:Floats=10, num_it:int=100, stop_div:bool=True, wd:float=None):

/opt/conda/lib/python3.6/site-packages/fastai/basic_train.py in fit(self, epochs, lr, wd, callbacks)
    200         callbacks = [cb(self) for cb in self.callback_fns + listify(defaults.extra_callback_fns)] + listify(callbacks)
    201         self.cb_fns_registered = True
--> 202         fit(epochs, self, metrics=self.metrics, callbacks=self.callbacks+callbacks)
    203 
    204     def create_opt(self, lr:Floats, wd:Floats=0.)->None:

/opt/conda/lib/python3.6/site-packages/fastai/basic_train.py in fit(epochs, learn, callbacks, metrics)
    104             if not cb_handler.skip_validate and not learn.data.empty_val:
    105                 val_loss = validate(learn.model, learn.data.valid_dl, loss_func=learn.loss_func,
--> 106                                        cb_handler=cb_handler, pbar=pbar)
    107             else: val_loss=None
    108             if cb_handler.on_epoch_end(val_loss): break

/opt/conda/lib/python3.6/site-packages/fastai/basic_train.py in validate(model, dl, loss_func, cb_handler, pbar, average, n_batch)
     61             if not is_listy(yb): yb = [yb]
     62             nums.append(first_el(yb).shape[0])
---> 63             if cb_handler and cb_handler.on_batch_end(val_losses[-1]): break
     64             if n_batch and (len(nums)>=n_batch): break
     65         nums = np.array(nums, dtype=np.float32)

/opt/conda/lib/python3.6/site-packages/fastai/callback.py in on_batch_end(self, loss)
    306         "Handle end of processing one batch with `loss`."
    307         self.state_dict['last_loss'] = loss
--> 308         self('batch_end', call_mets = not self.state_dict['train'])
    309         if self.state_dict['train']:
    310             self.state_dict['iteration'] += 1

/opt/conda/lib/python3.6/site-packages/fastai/callback.py in __call__(self, cb_name, call_mets, **kwargs)
    248         "Call through to all of the `CallbakHandler` functions."
    249         if call_mets:
--> 250             for met in self.metrics: self._call_and_update(met, cb_name, **kwargs)
    251         for cb in self.callbacks: self._call_and_update(cb, cb_name, **kwargs)
    252 

/opt/conda/lib/python3.6/site-packages/fastai/callback.py in _call_and_update(self, cb, cb_name, **kwargs)
    239     def _call_and_update(self, cb, cb_name, **kwargs)->None:
    240         "Call `cb_name` on `cb` and update the inner state."
--> 241         new = ifnone(getattr(cb, f'on_{cb_name}')(**self.state_dict, **kwargs), dict())
    242         for k,v in new.items():
    243             if k not in self.state_dict:

/opt/conda/lib/python3.6/site-packages/fastai/callback.py in on_batch_end(self, last_output, last_target, **kwargs)
    342         if not is_listy(last_target): last_target=[last_target]
    343         self.count += first_el(last_target).size(0)
--> 344         val = self.func(last_output, *last_target)
    345         if self.world:
    346             val = val.clone()

<ipython-input-25-f37731fdae06> in accuracy_1(input, targs)
      5     targs = targs.view(-1).long()
      6     n = targs.shape[0]
----> 7     input = input.argmax(dim=-1).view(n,-1)
      8     targs = targs.view(n,-1)
      9     return (input==targs).float().mean()

RuntimeError: shape '[70912, -1]' is invalid for input of size 64