Shortest Path calculation problem

%mat = [0,10,15,20;10,0,35,25;15,35,0,30;20,25,30,0]

pkg load io
mat = xlsread('distance matrix2.xlsx')
source = 1
len = length(mat)
vertex = zeros(1,len-1)
for i=1:len-1
 vertex(i)=i+1
end
minpath = intmax

num = factorial(len-1)
count=0
while(count<num)
current_pathweight=0
k=source
for i=1:len-1
current_pathweight=current_pathweight+mat(k,vertex(i))
k=vertex(i)
end
current_pathweight=current_pathweight+mat(k,source)
if(current_pathweight<minpath)
minpath=current_pathweight
end
vertex=myperms(vertex)
count = count+1
end

when i run shows error:

Undefined function or variable 'pkg'.

Error in main (line 2)

pkg load io

[KSSV]

This is a octave code.....remove the line pkg load io