import sys
sys.setrecursionlimit(100000+100)
N,Q = map(int,input().split())
G = {i:[] for i in range(1,N+1)}
for _ in range(N-1):
    a,b = map(int,input().split())
    G[a].append(b)
    G[b].append(a)
C = [0]*(N+1)
C0 = [[0,0] for _ in range(N+1)]
C0[1][0] = 1
val = 2
def dfs(i,p):
    global val
    for j in G[i]:
        if j==p:continue
        C0[j][0] = val
        val += 1
        dfs(j,i)
    C0[i][1] = val
    val += 1
dfs(1,0)
for i in range(1,N+1):
    C[i] = (C0[i][1]-C0[i][0])//2
ans = 0
for _ in range(Q):
    p,x = map(int,input().split())
    ans += (C[p]+1)*x
    print(ans)