Size mismatch error with the toturial

Hello,everyone,
I am learning the tutorial called Deep Learning with PyTorch: A 60 Minute Blitz on PyTorch website. My codes are the same as those of it, but there is a size mismatch error as shown below. Could anyone tell me why and how to solve it? Thank you:)
RuntimeError: size mismatch, m1: [80 x 5], m2: [400 x 120] at c:\a\w\1\s\tmp_conda_3.7_110509\conda\conda-bld\pytorch_1544094576194\work\aten\src\th\generic/THTensorMath.cpp:940

import torch.nn as nn
import torch.nn.functional as F  

class Net(nn.Module):
    def __init__(self):
        super(Net,self).__init__()
        self.conv1=nn.Conv2d(1,6,5)
        self.conv2=nn.Conv2d(6,16,5)
        self.fc1=nn.Linear(16*5*5,120)
        self.fc2=nn.Linear(120,84)
        self.fc3=nn.Linear(84,10)
    
    def forward(self,x):
        x=F.max_pool2d(F.relu(self.conv1(x)),(2,2))
        x=F.max_pool2d(F.relu(self.conv2(x)),2)
        x.view(-1,self.num_flat_features(x))
        x=F.relu(self.fc1(x))
        x=F.relu(self.fc2(x))
        x=self.fc3(x)
        return x
    
    def num_flat_features(self,x):
        size=x.size()[1:]
        num_features=1
        for s in size:
            num_features*=s
        return num_features

net=Net()
input=torch.randn(1,1,32,32)
out=net(input)
print(out)

Sorry for disturbance, I find the mistake. I missed x= in x=x.view(-1,self.num_flat_features(x)):sweat: