=== 그리디로 ===
{{{~cpp
// 10201 - Adventures in Moving: Part IV 
#include <iostream> 
using namespace std;

#define MAX_OIL 200 
#define MAX_SIZE 103
#define MAX_NUM 1000000000 

typedef struct 
{ 
    int length; 
    int price; 
}Station; 

static int totalLength;                /* 워털루에서 대도시까지의 거리 */ 
static int numStation;                /* 주유소 수 */ 
static Station station[MAX_SIZE];    /* 주유소 정보 */ 

inline  
int getDistance(int i)  
{  
    return station[i].length - station[i-1].length;  
} 

void input() 
{ 
    cin >> totalLength; 
	totalLength += 100;
    cin.get(); 
    numStation = 1;
	station[numStation].length = 0;
	station[numStation].price = 0;
    while (cin.peek() != EOF && cin.peek() != '\n') 
    { 
        numStation++; 
        cin >> station[numStation].length >> station[numStation].price; 
        cin.get(); 
    } 
    cin.get();
	numStation++;
	station[numStation].length = totalLength;
	station[numStation].price = 0;
} 

void process() 
{ 
	int maxmin, maxminprice , now = 1, tank = 100, go = 100, search = 2, cost = 0;
	
    while(now != numStation)
	{
		maxmin = 0;
		maxminprice = 1000000;
		while(station[now].length + go >= station[search].length)
		{
			// 서치의 가격이 작거나 같을때
			if(station[now].price > station[search].price)
			{
				if(station[search].length - station[now].length >= tank)
				{				
					cost += (station[search].length - station[now].length - tank)*station[now].price;
					tank = 0;
				}
				else
					tank = tank - station[search].length + station[now].length;
				now = search++;
				maxmin = 0;
				break;
			}
			// 서치의 가격이 클때 
			else
			{
				if(maxminprice > station[search].price)
				{
					maxmin = search;
					maxminprice = station[search].price;
				}
				search++;
			}
		}
		// 작은게 없을때
		if(now + 1 == search && station[now].length + go < station[search].length)
		{
			cout << "Impossible\n";
			return;
		}
		if(maxmin)
		{
			if(station[maxmin].length - station[now].length >= tank)
			{
				cost += (200 - tank)*station[now].price;
				tank = go - station[maxmin].length + station[now].length;
			}
			else
				tank = tank - station[maxmin].length + station[now].length;
			
			now = maxmin;
			search = now +1;
		}
		go = 200;
	}

	cout << cost << endl;
} 

int main() 
{ 
    int numCase; 
    cin >> numCase; 
    cin.get(), cin.get(); 
    for (int i = 0; i < numCase; i++) 
    { 
        input(); 
        process(); 
        if (i != numCase - 1) 
            cout << endl; 
    } 
    return 0; 
} 
}}}