1-2

#include <stdio.h>

int main() {
    double a[3][4], sum;

    for (int i = 0; i < 3; ++i) {
        for (int j = 0; j < 4; ++j) {
            scanf("%lf", &a[i][j]);
        }
    }

    for (int i = 0; i < 3; ++i) {
        for (int j = 0; j < 4; ++j) {
            sum += a[i][j];
        }
    }

    printf("%lf", sum);

    return 0;
}