#include <cstdio>
#include <algorithm>
#define N 100010
using namespace std;
typedef long long ll;
int head[N] , to[N << 1] , len[N << 1] , next[N << 1] , cnt , log[N << 1] , pos[N] , tot;
int si[N] , mx[N] , sum , root , vis[N] , fa[N] , val[N << 1] , rt , num[N];
ll deep[N] , md[20][N << 1] , va[N] , vb[N];
void add(int x , int y , int z)
{to[++cnt] = y , len[cnt] = z , next[cnt] = head[x] , head[x] = cnt;
}
void dfs(int x , int fa)
{int i;pos[x] = ++tot , md[0][tot] = deep[x];for(i = head[x] ; i ; i = next[i])if(to[i] != fa)deep[to[i]] = deep[x] + len[i] , dfs(to[i] , x) , md[0][++tot] = deep[x];
}
ll dis(int x , int y)
{ll t = deep[x] + deep[y];x = pos[x] , y = pos[y];if(x > y) swap(x , y);int k = log[y - x + 1];return t - 2 * min(md[k][x] , md[k][y - (1 << k) + 1]);
}
void getroot(int x , int fa)
{int i;si[x] = 1 , mx[x] = 0;for(i = head[x] ; i ; i = next[i])if(!vis[to[i]] && to[i] != fa)getroot(to[i] , x) , si[x] += si[to[i]] , mx[x] = max(mx[x] , si[to[i]]);mx[x] = max(mx[x] , sum - si[x]);if(mx[x] < mx[root]) root = x;
}
void solve(int x)
{int i;vis[x] = 1;for(i = head[x] ; i ; i = next[i])if(!vis[to[i]])sum = si[to[i]] , root = 0 , getroot(to[i] , 0) , fa[root] = x , val[i] = root , solve(root);
}
ll calc(int x)
{int i;ll ans = 0;for(i = x ; i ; i = fa[i]) ans += va[i] + num[i] * dis(x , i);for(i = x ; fa[i] ; i = fa[i]) ans -= vb[i] + num[i] * dis(x , fa[i]);return ans;
}
ll query()
{int x = rt , i , y;ll mn , t;while(1){mn = calc(x) , y = x;for(i = head[x] ; i ; i = next[i])if(val[i] && (t = calc(to[i])) < mn)mn = t , y = val[i];if(x == y) break;x = y;}return mn;
}
int main()
{int n , m , i , j , x , y , z;scanf("%d%d" , &n , &m);for(i = 1 ; i < n ; i ++ ) scanf("%d%d%d" , &x , &y , &z) , add(x , y , z) , add(y , x , z);dfs(1 , 0);for(i = 2 ; i <= tot ; i ++ ) log[i] = log[i >> 1] + 1;for(i = 1 ; (1 << i) <= tot ; i ++ )for(j = 1 ; j <= tot - (1 << i) + 1 ; j ++ )md[i][j] = min(md[i - 1][j] , md[i - 1][j + (1 << (i - 1))]);mx[0] = 1 << 30 , sum = n , getroot(1 , 0) , rt = root , solve(root);while(m -- ){scanf("%d%d" , &x , &y);for(i = x ; i ; i = fa[i]) va[i] += y * dis(x , i) , num[i] += y;for(i = x ; fa[i] ; i = fa[i]) vb[i] += y * dis(x , fa[i]);printf("%lld\n" , query());}return 0;
}