rt，云斗 50pts，思路就是分段二分，代码挺丑的

本地数据可能造的太随机了，拍不出来

#include <bits/stdc++.h>
#define LL long long

using namespace std;

inline int read()
{
	int x = 0,f = 1;char ch = getchar();
	while(!isdigit(ch)) (ch == '-') && (f = -1),ch = getchar();
	while(isdigit(ch)) x = x*10+ch-48,ch = getchar();
	return x*f;
}

const int N = 1e5+10;

LL n,k,x,y,_x[N],_y[N],s1[N],s2[N];

int main()
{
	freopen("sj.out","r",stdin);
	freopen("wind.out","w",stdout);
	int T = read();
	while(T--)
	{
		n = read(),k = read(),x = read(),y = read();
		LL m = 1e18;bool f = 0;
		for (int i = 0;i < n;i++)
		{
			_x[i] = read(),_y[i] = read();
			s1[i] = (i ? s1[i-1] : 0)+_x[i],s2[i] = (i ? s2[i-1] : 0)+_y[i];
		}
		if(x == 0 && y == 0){printf("0\n");continue;}
		for (LL i = 0;i < n;i++)
		{
			LL x_1 = x-s1[i],y_1 = y-s2[i];
			if(llabs(x_1)+llabs(y_1) <= k*(i+1))
				{f = 1,m = min(m,i+1);continue;}
			if (k == 0)
			{
				if (!s1[n-1] || !s2[n-1])
				{
					if (!s1[n-1] && !x_1 && s2[n-1] && y_1%s2[n-1] == 0 && y_1/s2[n-1] >= 0) f = 1,m = min(m,i+1+y_1/s2[n-1]*n);
					if (!s2[n-1] && !y_1 && s1[n-1] && x_1%s1[n-1] == 0 && x_1/s1[n-1] >= 0) f = 1,m = min(m,i+1+x_1/s1[n-1]*n);
					continue;
				}
				if (x_1%s1[n-1] == 0 && y_1%s2[n-1] == 0 && x_1/s1[n-1] == y_1/s2[n-1] && x_1/s1[n-1] >= 0) f = 1,m = min(m,i+1+x_1/s1[n-1]*n);
				continue;
			}
			if (x_1*s1[n-1] > 0)
			{
				if (y_1*s2[n-1] > 0)
				{
					LL p1 = llabs(x_1/s1[n-1]),p2 = llabs(y_1/s2[n-1]);bool fl = 0;
					if (p1 > p2) swap(p1,p2);
					LL l = 1,r = p1;
					if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
					while(l < r)
					{
						LL mid = (l+r)/2;
						if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
						else l = mid+1;
					}
					if (fl) f = 1,m = min(m,i+1+l*n);
					else
					{
						l = p1+1,r = p2;
						if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
						while(l < r)
						{
							LL mid = (l+r)/2;
							if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
							else l = mid+1;
						}
						if (fl) f = 1,m = min(m,i+1+l*n);
						else
						{
							l = p2+1,r = r = 1e18/n/max({k,llabs(s1[n-1]),llabs(s2[n-1])});
							if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
							while(l < r)
							{
								LL mid = (l+r)/2;
								if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
								else l = mid+1;
							}
							if (fl) f = 1,m = min(m,i+1+l*n);
						}
					}
				}
				else
				{
					LL p = llabs(x_1/s1[n-1]);bool fl = 0;
					LL l = 1,r = p;
					if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
					while(l < r)
					{
						LL mid = (l+r)/2;
						if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
						else l = mid+1;
					}
					if (fl) f = 1,m = min(m,i+1+l*n);
					else
					{
						l = p+1,r = 1e18/n/max({k,llabs(s1[n-1]),llabs(s2[n-1])});
						if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
						while(l < r)
						{
							LL mid = (l+r)/2;
							if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
							else l = mid+1;
						}
						if (fl) f = 1,m = min(m,i+1+l*n);
					}
				}
			}
			else
			{
				if (y_1*s2[n-1] > 0)
				{
					LL p = llabs(y_1/s2[n-1]);bool fl = 0;
					LL l = 1,r = p;
					if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
					while(l < r)
					{
						LL mid = (l+r)/2;
						if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
						else l = mid+1;
					}
					if (fl) f = 1,m = min(m,i+1+l*n);
					else
					{
						l = p+1,r = 1e18/n/max({k,llabs(s1[n-1]),llabs(s2[n-1])});
						if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
						while(l < r)
						{
							LL mid = (l+r)/2;
							if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
							else l = mid+1;
						}
						if (fl) f = 1,m = min(m,i+1+l*n);
					}
				}
				else
				{
					LL l = 1,r = 1e18/n/max({k,llabs(s1[n-1]),llabs(s2[n-1])});bool fl = 0;
					if(l == r && (l*n+i+1)*k >= llabs(x_1-s1[n-1]*l)+llabs(y_1-s2[n-1]*l)) fl = 1;
					while(l < r)
					{
						LL mid = (l+r)/2;
						if((mid*n+i+1)*k >= llabs(x_1-s1[n-1]*mid)+llabs(y_1-s2[n-1]*mid)) r = mid,fl = 1;
						else l = mid+1;
					}
					if (fl) f = 1,m = min(m,i+1+l*n);
				}
			}
		}
		if(f) printf("%lld\n",m);
		else printf("-1\n");
	}
	return 0;
}