public class Tttt {
public int a;
public Tttt(int b){
a=b;
}
public int q(){
int count=0 ;
for(int i=1;i<=a/2;i++){
count = count+part(i,a-i);
}
return count;
}
public int part(int low,int high){
int count = 0;
if(low >= high)
return 0;
else{
count = part(low+1,high-low-1)+1;
while(low + high != a && (--high - ++low > 0)){
int temp = 0;
temp = part(low+1,high-low-1)+1;
count = count + temp;
}
}
return count;
}
public static void main(String[] args){
Tttt t = new Tttt(20); //可以通过改变括号里的值来算出任意的整数和为n的组合数
System.out.println(t.q());
}
}