#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int N,a[11][11],c; int b; for(int i=0;i<N;i++){ for(int j=0;j<N;j++){ cin>>a[i][j]; if(i==j) b+=a[i][j]; if(i+j==N-1) b+=a[i][j]; } } for(int i=0;i<N;i++){ for(int j=0;j<N;j++){ if(i==j) b+=a[i][j]; if(i+j==N-1) b+=a[i][j]; if(N%2!=0) c=a[N/2][N/2]; } } cout<<b-c<<endl; return 0; }