Bitwise operations in C

# include<stdio.h>
int main(){
	int a, b, option, res;
	printf("Enter a and b\n");
	scanf("%d %d", &a, &b);
	do{
		printf("MENU\n 1.AND\n 2.OR\n 3.NOT \n 4.XOR\n 0.Exit\n");
		printf("Enter choice: ");
		scanf("%d", &option);
		switch(option){
			case 1:
				res = a & b;
				printf("%d AND %d = %d\n", a, b, res);
			break;
			case 2:
				res = a | b;
				printf("%d OR %d = %d\n", a, b, res);
			break;
			case 3:
				res = ~a;
				printf("NOT of %d = %d\n", a, res);
				res = ~b;
				printf("NOT of %d = %d\n", b, res);
			break;
			case 4:
			res = a ^ b;
				printf("%d XOR %d = %d\n", a, b, res);
			break;
			default:
			break;
		}
		printf("\n");
	}while(option);
    return 0;
}