#include <stdio.h>
 
int main() {
    int M, N;
    int a[100][100];
    int i, j;
    int jumlah = 0;
 
    scanf("%d %d", &M, &N);
 
    for(i = 0; i < M; i++) {
        for(j = 0; j < N; j++) {
            scanf("%d", &a[i][j]);
        }
    }
 
    for(i = 0; i < M; i++) {
        for(j = 0; j < N; j++) {
 
            if(i == 0 || i == M-1 || j == 0 || j == N-1) {
                jumlah += a[i][j];
            }
        }
    }
 
    printf("%d\n", jumlah);
 
    return 0;
}
 

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MyA0IAoxIDIgMyA0CjUgNiA3IDgKOSAwIDEgMg==

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1 2 3 4
5 6 7 8
9 0 1 2