C

int main() {

int** arr = malloc(6 * sizeof(int*));

for (int i = 0; i < 6; i++) {
    *(arr + i) = malloc(6 * (sizeof(int)));

    char** arr_item_temp = split_string(rtrim(readline()));

    for (int j = 0; j < 6; j++) {
        int arr_item = parse_int(*(arr_item_temp + j));

        *(*(arr + i) + j) = arr_item;
    }
}

int countk = 0;
int countl = 0;
int sum = 0;
int sum_max = -63;
int k = 0;
int l = 0;

for (int i = 0; i < 4; i++) {

    for (int j = 0; j < 4; j++) {
            countk = 0;
            for (k=i; k < i+3; k++) {
                countl = 0;
                countk++;
                for (l=j; l < j+3; l++) {
                    countl++;
                    if(countk==2){
                        if (countl==2) {
                        sum+= *(*(arr + k)+l);
                        }
                    }else {
                        sum+= *(*(arr + k)+l);
                    }         
                }//end for l
            }//end for k
        if(sum>sum_max){
            sum_max=sum;
        }
        sum=0;    
    }//end for j
}//end for i 

printf("%i",sum_max);

return 0;

}