#include<cstdlib>#include<cstdio>#include<cstring>#include<algorithm>#include<deque>#ifdef WIN32#define fmt64 "%I64d"#else#define fmt64 "%lld"#endifusing namespace std;const int maxn = (int)1.5e5, inf = 0x3f3f3f3f;struct E{    int t,w,last;}e[maxn * 2];struct Q{    int w,l;}data[maxn];int cmp(Q x, Q y){    if(x.w != y.w) return x.w < y.w;    return x.l < y.l;}int last[maxn],cnt;int node,tmax;int n,L,W;int size;struct BIT{    int bt[maxn];    int lowbit(int x){        return x & (-x);    }    void ins(int pos,int val){        while(pos <= n){            bt[pos] += val;            pos += lowbit(pos);        }    }    int qer(int pos){        int ret = 0;        while(pos > 0){            ret += bt[pos];            pos -= lowbit(pos);        }        return ret;    }}bit;void add(int x,int y,int w){    e[++cnt] = (E){y,w,last[x]}; last[x] = cnt;    e[++cnt] = (E){x,w,last[y]}; last[y] = cnt;}int sz[maxn],vis[maxn];int root;void getroot(int x,int fa){    sz[x] = 0;    int Max = 0;    for(int i = last[x]; i; i = e[i].last)        if(e[i].t != fa && !vis[e[i].t]){            getroot(e[i].t, x);            Max = max(Max, sz[e[i].t] + 1);            sz[x] += sz[e[i].t] + 1;        }    Max = max(Max, node - sz[x] - 1);    if(tmax >= Max) root = x, tmax = Max;}int add1,add2;long long ans;void getdata(int x,int fa,int sumw,int suml){                        int cost1 = sumw + add1, cost2 = suml + add2;    if(cost1 <= W && cost2 <= L)        data[++size] = (Q){cost1,cost2};    for(int i = last[x]; i; i = e[i].last)        if(e[i].t != fa && !vis[e[i].t])            getdata(e[i].t, x, sumw + e[i].w, suml + 1);}long long process(){    sort(data + 1, data + size + 1, cmp);    int h = 1,t = size;    long long ret = 0;    deque<Q>q;    deque<int>qq;    while(h < t || !q.empty()){        while(!q.empty() && qq.back() <= h){            bit.ins(q.back().l, -1);            q.pop_back(), qq.pop_back();        }        while(!q.empty() && q.front().w + data[h].w > W){            bit.ins(q.front().l, -1);            q.pop_front(), qq.pop_front();        }        if(data[t].w + data[h].w > W)            { t--; continue; }        else{            while(h < t && data[t].w + data[h].w <= W){                bit.ins(data[t].l, 1);                q.push_back(data[t]); qq.push_back(t--);            }            ret += bit.qer(L - data[h++].l);        }            }    return ret;}long long calc(int x,int ad1,int ad2){        size = 0;    add1 = ad1; add2 = ad2;    getdata(x,0,0,0);    return process();}void solve(int x){    ans += calc(x, 0, 0);    vis[x] = 1;    for(int i = last[x]; i; i = e[i].last)        if(!vis[e[i].t]){            ans -= calc(e[i].t, e[i].w, 1);            node = sz[e[i].t];            tmax = inf;            getroot(e[i].t, root = 0);            solve(root);        }}void work(){    node = n; tmax = inf;    getroot(1,0);    solve(root);}int main(){    freopen("pair.in","r",stdin);    freopen("pair.out","w",stdout);    scanf("%d %d %d",&n,&L,&W);    for(int i = 2; i <= n; ++i){        int p,w; scanf("%d %d",&p,&w);        add(i,p,w);    }    work();    printf(fmt64"\n", ans);    return 0;}