#include<stdio.h>
void main()
{
   int a;
   char b=y;
   while(b==y)
   {
   printf("Input angle of your shape :");
   scanf("%d", &a);
   while(a<3)
   {
      printf("\nReinput your angle");
      scanf("%d",&a);
   }
   printf("\nSum of inner angle :%d", (a-2)*180);
   printf("Do you want to continue(y/n) :");
   scanf("%c", &b);
   }
   printf("Good bye...");
}