#include <bits/stdc++.h>
using namespace std;
bool stB;
namespace SOL {
void debug(const char *msg, ...) {
#ifdef CLESIP
va_list arg;
static char pbString[512];
va_start(arg,msg);
vsprintf(pbString,msg,arg);
cerr << "[DEBUG] " << pbString << "\n";
va_end(arg);
#endif
}
#define PASSED cerr << "PASSED " << __FUNCTION__ << " #" << __LINE__ << "\n";
using i64 = long long;
using i128 = __int128_t;
template <typename T, typename L> void chkmax(T &x, L y) { if (x < y) x = y; }
template <typename T, typename L> void chkmin(T &x, L y) { if (y < x) x = y; }
const int N = 6e5 + 10;
int n, m, lc[N], rc[N], rt[N], dis[N], a[N], fa[N], cnt, deg[N];
i64 val[N];
int merge(int x, int y) {
if (!x || !y)
return x | y;
if (val[x] < val[y])
swap(x, y);
rc[x] = merge(rc[x], y);
if (dis[lc[x]] < dis[rc[x]])
swap(lc[x], rc[x]);
dis[x] = rc[x] ? dis[rc[x]] + 1 : 0;
return x;
}
void pop(int x) {
rt[x] = merge(lc[rt[x]], rc[rt[x]]);
}
void ___solve() {
cin >> n >> m;
for (int i = 2; i <= n + m; i ++)
cin >> fa[i] >> a[i], ++ deg[fa[i]];
for (int i = n + m; i > 1; i --) {
i64 l = 0, r = 0;
if (i <= n) {
for (int j = 1; j < deg[i]; j ++)
pop(i);
r = val[rt[i]];
pop(i);
l = val[rt[i]];
pop(i);
}
l += a[i], r += a[i];
val[++ cnt] = l, val[++ cnt] = r;
rt[fa[i]] = merge(rt[fa[i]], merge(rt[i], merge(cnt - 1, cnt)));
}
for (int j = 1; j <= deg[1]; j ++)
pop(1);
i64 ans = 0;
for (int i = 2; i <= n + m; i ++)
ans += a[i];
while (rt[1] > 0) {
ans -= val[rt[1]], pop(1);
}
cout << ans << "\n";
}
}
bool edB;
signed main() {
// cerr << "Memory: " << (&stB - &edB) / 1024.0 / 1024.0 << "MB\n";
ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
SOL::___solve();
return 0;
}
