C++ :

#include <bits/stdc++.h>
using namespace std;

int main(){
	//4个点
	int x[4];
	int y[4];
	int i,j;
	//读入4个点的坐标
	for(i = 0;i < 4;i++){
		cin>>x[i];
		cin>>y[i];
	} 
	
	sort(x,x + 4);
	sort(y,y + 4);
	//统计4个点中x和y最多相同的数值有几个
	int cx = 0,cy = 0;//存最多相同值的数量
	for(i = 0;i < 3;i++){
		for(j = i + 1;j < 4;j++){
			if(x[i] == x[j]) cx++;
			if(y[i] == y[j]) cy++;
		}
	} 
	
	if(cx == 6 || cy == 6){
		cout<<"zhisi"<<endl;
	}else if(cx == 2 && cy == 2){
		cout<<"fangsi"<<endl;
	}else if(cx == 3 || cy == 3){
		//曲四或丁四
		if(cx == 3){
			//中间2个相同是丁四
			if(y[1] == y[2]){
				cout<<"dingsi"<<endl;
			}else{
				cout<<"qusi"<<endl;
			}
		} else{
			if(x[1] == x[2]){
				cout<<"dingsi"<<endl;
			}else{
				cout<<"qusi"<<endl;
			}
		}
	}else{
		cout<<"wansi"<<endl;
	}
	
}