if (var1 < 0 && var2 < 0) {
result = 0;
} else {
result = Enum.calc(var1, var2, operation);
System.out.println("Результат RomanNum:");
String resultRoman = Enum.convertNumToRoman(result);
System.out.println(stb0 + " " + operation + " " + strings + " = " + resultRoman);
}
var1 = Enum.convertRomanToArab(stb0);
if (var1 == -1) var1 = Integer.parseInt(stb0);
var2 = Enum.convertRomanToArab(strings);
if (var2 == -1) var2 = Integer.parseInt(strings);
result = Enum.calc(var2, var2, operation);
System.out.println("Результат ArabNum:");
System.out.println(var1 + " " + operation + " " + var2 + " = " + result);