Let the integer part of (5-radical 5) be a and the decimal part be B, then a-b=___

Let the integer part of (5-radical 5) be a and the decimal part be B, then a-b=___

2<√5<3
5-2>5-√5>5-3
3>5-√5>2
∴a=2
b=5-√5-2=3-√5
∴a-b=2-3+√5=-1+√5