只过 Sub1&Sub3，其他的全是 Wa

#include<bits/stdc++.h>
using namespace std;
const int siz = 3e5;
int n,m,q,t,lastans;
struct node{int from,to,w;} edge[500005];
int root[500005];
namespace shiro
{
	#define mid (l+r>>1)
	int cnt;
	struct node{int ls,rs,sum;} tr[500005<<2];
	void pushup(int k){tr[k].sum = tr[tr[k].ls].sum+tr[tr[k].rs].sum;}
	void build(int &k,int l,int r)
	{
		k = ++cnt;
		if (l == r) return ;
		build(tr[k].ls,l,mid);
		build(tr[k].rs,mid+1,r);
	}
	int insert(int k,int l,int r,int x,int a)
	{
		int u = ++cnt;
		tr[u] = tr[k];
		if (l == r)
		{
			tr[u].sum += a;
			return u;
		}
		if (x <= mid) tr[u].ls = insert(tr[u].ls,l,mid,x,a);
		else tr[u].rs = insert(tr[u].rs,mid+1,r,x,a);
		pushup(u);
		return u;
	}
	int query(int rt,int l,int r,int x,int y)
	{
		int res = 0;
		if (l >= x && r <= y)
			return tr[rt].sum;
		if (x <= mid) res += query(tr[rt].ls,l,mid,x,y);
		if (y > mid) res += query(tr[rt].rs,mid+1,r,x,y);
		return res;
	}
}
namespace elia
{
	int stk[5000005],top;
	struct Splay{int ch[2],val,mi,fa,rev;} tr[5000005];
	bool isroot(int x){return tr[tr[x].fa].ch[0]!=x&tr[tr[x].fa].ch[1]!=x;}
	void pushup(int x)
	{
		tr[x].mi = tr[tr[tr[x].ch[0]].mi].val<tr[tr[tr[x].ch[1]].mi].val?tr[tr[x].ch[0]].mi:tr[tr[x].ch[1]].mi;
		tr[x].mi =tr[x].val<tr[tr[x].mi].val?x:tr[x].mi;
	}
	void pushdown(int x)
	{
		if (tr[x].rev)
		{
			tr[x].rev ^= 1;
			swap(tr[x].ch[0],tr[x].ch[1]);
			if (tr[x].ch[0]) tr[tr[x].ch[0]].rev ^= 1;
			if (tr[x].ch[1]) tr[tr[x].ch[1]].rev ^= 1;
		}
	}
	void rotate(int x)
	{
		int y = tr[x].fa,z = tr[y].fa,pd = tr[y].ch[1]==x;
		if (!isroot(y)) tr[z].ch[tr[z].ch[1]==y] = x; tr[x].fa = z;
		tr[y].ch[pd] = tr[x].ch[pd^1]; tr[tr[x].ch[pd^1]].fa = y;
		tr[x].ch[pd^1] = y; tr[y].fa = x;
		pushup(y); pushup(x);
	}
	void splay(int x)
	{
		int u = x;
		stk[++top] = u;
		while (!isroot(u)) stk[++top] = u=tr[u].fa;
		while (top) pushdown(stk[top--]);
		while (!isroot(x))
		{
			int y = tr[x].fa,z = tr[y].fa;
			if (!isroot(y)) (tr[y].ch[0]==x)^(tr[z].ch[0]==y)?rotate(x):rotate(y);
			rotate(x);
		}
	}
	void access(int x){for(int y=0;x;y=x,x=tr[x].fa) splay(x),tr[x].ch[1]=y,pushup(x);}
	void makeroot(int x){access(x); splay(x); tr[x].rev ^= 1;}
	int findroot(int x){access(x); splay(x); while(tr[x].ch[0]) x=tr[x].ch[0]; return x;}
	void split(int x,int y){makeroot(x); access(y); splay(y);}
	void link(int x,int y){makeroot(x); tr[x].fa = y;}
	void cut(int x,int y){split(x,y); if(tr[y].ch[0]==x) tr[x].fa=tr[y].ch[0]=0;}
	void change(int x,int v){makeroot(x); tr[x].val=v; pushup(x);}
	void add(int id){link(edge[id].from,id+siz); link(id+siz,edge[id].to); change(id+siz,edge[id].w);}
	void del(int id){cut(edge[id].from,id+siz); cut(id+siz,edge[id].to);}
	void sol(int id)
	{
		split(edge[id].from,edge[id].to);
		int pos = tr[edge[id].to].mi;
		root[id] = shiro::insert(root[id],1,m,pos-siz,-1);
		del(pos-siz);
		
	}
}
using namespace elia;
void modify(int id)
{
	root[id] = shiro::insert(root[id],1,m,id,1);
	if (findroot(edge[id].from) == findroot(edge[id].to))
		sol(id);
	add(id);
}
int main()
{
	cin >> n >> m >> q >> t;
	for (int i = 0; i <= n+siz; i++) tr[i].mi = i,tr[i].val = 2e9;
	shiro::build(root[0],1,m);
	for (int i = 1; i <= m; i++)
	{
		cin >> edge[i].from >> edge[i].to;
		edge[i].w = i;
		root[i] = root[i-1];
		if (edge[i].from == edge[i].to)
			continue;
		modify(i);
	}
	int l,r;
	while (q--)
	{
		cin >> l >> r;
		if (t) l = (l+lastans)%m+1,r = (r+lastans)%m+1;
		if (l > r) swap(l,r);
		lastans = n-shiro::query(root[r],1,m,l,r);
		cout << lastans << '\n';
	}
	return 0;
}