#include <bits/stdc++.h>
using namespace std;
 
int N,s,e;
const int MaxN=3e4;
struct LINE{
	int s,e;
	LINE(int s=0, int e=0):s(s),e(e){}
}line[MaxN];
bool comp(LINE lhs, LINE rhs){
	return lhs.s<rhs.s;
}
int main() {
	int ans=0,case_=1;
	while(cin>>N){
		for(int n=0;n<N;n++){
			cin>>s>>e;
			line[n].s=s;
			line[n].e=e;
		}
		sort(line,line+N,comp);
		for(int n=0;n<N;n++)
			for(int m=n+1;m<N;m++){
				if(line[n].e>line[m].s)
					ans++;
				}
 
			int total=(N*(N-1))/2;
			cout<<"Case "<<case_<<": "<<total-ans<<"\n";
			case_++;
	}
	return 0;
}

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2
0 10
10 20
2
0 10
5 8
2
0 10
5 20
2
0 10
-5 5
2
0 10
0 10
2
0 10
5 10
5
1 5
1 5
3 10
3 10
3 10