/*线段树扫描线问题，感觉可以作为这类问题的模板。问过师兄以后才过的。。。

按y轴建线段树。*/

struct node{int l, r, c;    //c表示被覆盖的情况，不为0表示被覆盖    double sum, len;    //len表示当前段的长度，sum表示有效长度。就是可以计入求面积的长度}node[N<<2];

struct line{double x;　　//记录x坐标    double y1;   double y2;    //y1，y2用来记录平行y轴的线段的两个端点，    int flag;    //标记是左边的边还是右边的边}l[N];

//My Code:

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#define L(t) t << 1#define R(t) t << 1 | 1

using namespace std;

const int N = 210;

struct node{int l, r, c;double sum, len;}node[N<<2];

struct line{double x;double y1;double y2;int flag;}l[N];

double y[N];

bool cmp(line a, line b){return a.x < b.x;}

void creat(int t, int l, int r){    node[t].l = l;    node[t].r = r;    node[t].c = 0;    node[t].sum = 0;    node[t].len = y[r] - y[l];if(l + 1 == r)    return ;int mid = (l + r) >> 1;    creat(L(t), l, mid);    creat(R(t), mid, r);}

void updata_sum(int t){if(node[t].c > 0)    node[t].sum = node[t].len;else if(node[t].r != node[t].l + 1)    node[t].sum = node[L(t)].sum + node[R(t)].sum;else    node[t].sum = 0;}

void updata(int t, int l, int r, int c){if(node[t].l == l && node[t].r == r){if(c)    node[t].c ++;else    node[t].c --;        updata_sum(t);return ;    }int mid = (node[t].l + node[t].r) >> 1;if(l >= mid)    updata(R(t), l, r, c);else if(r <= mid)    updata(L(t), l, r, c);else{        updata(L(t), l, mid, c);        updata(R(t), mid, r, c);    }    updata_sum(t);}

int find(double key, int n){int l = 1, r = n, mid;while(l <= r){        mid = (l + r) >> 1;if(y[mid] == key)    return mid;else if(y[mid] > key)    r = mid-1;else    l = mid + 1;    }return 0;}

int main(){//freopen("data.in", "r", stdin);

int t, n, m, i, cas = 0;double x1, x2, y1, y2, ans;while(scanf("%d", &t), t){        m = 1;while(t--){            scanf("%lf%lf%lf%lf", &x1, &y1, &x2, &y2);            y[m] = y1; l[m].x = x1; l[m].y1 = y1; l[m].y2 = y2; l[m].flag = 1; m++;             y[m] = y2; l[m].x = x2; l[m].y1 = y1; l[m].y2 = y2; l[m].flag = 0; m++;        }        sort(y+1, y+m);        sort(l+1, l+m, cmp);        m--; n = 2;for(i = 1; i < m; i++)if(y[i] != y[i+1])    y[n++] = y[i+1];        n--; creat(1, 1, n);for(ans = 0, i = 1; i < m; i++){if(l[i].flag)    updata(1, find(l[i].y1, n), find(l[i].y2, n), 1);else    updata(1, find(l[i].y1, n), find(l[i].y2, n), 0);            ans += node[1].sum * (l[i+1].x - l[i].x);        }        printf("Test case #%d\nTotal explored area: %.2lf\n\n", ++cas, ans);    }return 0;}