#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

const int maxn = ;

long long n, head[maxn], nextt[maxn * ], tot = , to[maxn * ], w[maxn * ], num[maxn], fa[maxn], d[maxn], m;

long long ans;

void add(long long x, long long y, long long z)

{

    to[tot] = y;

    w[tot] = z;

    nextt[tot] = head[x];

    head[x] = tot++;

}

void dfs(long long u, long long fa)

{

    for (int i = head[u]; i; i = nextt[i])

    {

        int v = to[i];

        if (v != fa)

        {

            dfs(v, u);

            num[u] += num[v];

            ans += w[i] * num[v] * (n - num[v]);

        }

    }

    num[u]++;

}

int main()

{

    scanf("%lld", &n);

    for (int i = ; i <= n; i++)

    {

        long long x, y;

        scanf("%lld%lld", &x, &y);

        fa[i] = x;

        d[i] = y;

        add(x, i, y);

    }

    dfs(, fa[]);

    printf("%lld\n", ans);

    scanf("%lld", &m);

    for (int i = ; i <= m; i++)

    {

        long long a, b;

        scanf("%lld%lld", &a, &b);

        ans += num[a] * (n - num[a]) * (b - d[a]);

        printf("%lld\n", ans);

        d[a] = b;

    }

    return ;

}