private static char eva(int p) {
		int rank;
		char c;

		if (p < 0 || p > 100)
			c = 'X';
		else {
			rank = p/10;

			switch (rank) {
				case 6: c = 'C'; break;
				case 7: c = 'B'; break;
				case 8: c = 'A'; break;
				case 9:
				case 10: c = 'S'; break;
				default: c = 'D';
			}
		}

		return c;
	}