Треугольник со сторонами Даны длины 3-х отрезков

Uses crt; var a,b,c: integer; beginread (a); read (b); read (c); if (a+b) >c) and (a+c) >b) and (b+c) >a) thenbeginif (a=b) and (b<>c) or (a=c) and (c<>b) or (b=c) and (c<>a) then writeln ('Triangle is isosceles'); if (a=b) and (b=c) and (a=c) then writeln ('Triangle is equilateral'); if (a<>b) and (a<>c) and (b<>c) then writeln ('Triangle is scalene'); endelse writeln ('Triangle is invalid'); end.