#include <stdio.h> 
#include <math.h> 
#include <stdlib.h> 
#include <ctype.h> 
void menu() {
	char R1 = ' ';
	char R2 = ' ';
	//int Xstart = 0; скорее всего здесь другой тип
	//int Xend = 0;
	//int deltaX = 0;
	int flag = 0;
	char radius = ' ';
	char k = ' ';
	printf("Laba №2,  nomer variant\n");
	printf(" name/surname");
	while (1 == 1) {
		
		if (flag == 0) {
			printf("Input R1:\n");
			scanf_s("%c", &R1);
			fflush(stdin);
			if ((!isdigit(R1)) || (R1 <= 0)) {
				printf("Wrong input parameter, {Radius should be greater than zero and should be a digit}. Type ‘y’ for repeat, or any other for exit from application\n");
				system("pause");
				scanf_s("%c", &k);
				fflush(stdin);
				if (k == 'y') {
					flag = 1;
					continue;
				}
				else {
					flag = 0;
					continue;
				}
			}
			else{
				flag = 0;
				radius = atoi(&R1);
				
			}
			

			
	}

	}

}
int main(void) {

	menu();
	return 0;
}