#include <stdio.h>

#define SCALE 92
#define CMIN -73
#define CMAX 73

int CX[3], CY[3];
long long RX[3], RY[3], dx, dy;
int i, x, y, cmin, cmax, cnt;

int main() {
	for (i = 0; i < 3; i++) {
		scanf("%d %d %lld %lld", &(CX[i]), &(CY[i]), &(RX[i]), &(RY[i]));
		CX[i] *= SCALE;
		CY[i] *= SCALE;
		RX[i] *= SCALE;
		RY[i] *= SCALE;
		RX[i] *= RX[i];
		RY[i] *= RY[i];
	}

	cmin = CMIN * SCALE;
	cmax = CMAX * SCALE;
	cnt = 0;

	for (x = cmin; x <= cmax; x++)
		for (y = cmin; y <= cmax; y++) {
			for (i = 0; i < 3; i++) {
				dx = (x - CX[i]) * (x - CX[i]);
				dy = (y - CY[i]) * (y - CY[i]);
				if (dx * RY[i] + dy * RX[i] <= RX[i] * RY[i])
					break;
			}
			if (i < 3) cnt++;
		}

	//fprintf(stderr, "cnt=%d\n", cnt);

	printf("%.6lf\n", (double) cnt / (double) (SCALE * SCALE));
	return 0;
}