struct course
{
	int num_A;
	char name[100];
	char nature[20];
	int num_B;
	int num_C;
	int num_D;
	int score;
	char term[20];
}a;
struct student
{
	int num_A;
	char name[100];
}b;
struct check
{
	int num_A;
	char name[100];
}c;