import sys
sys.setrecursionlimit(10 ** 8)

N,Q = map(int, input().split())
L = [[] for i in range(N+1)]
for i in range(N-1):
    a,b = map(int, input().split())
    L[a].append(b)
    L[b].append(a)
C = [0]*(N+1)

DE = [0]*(N+1)
def dfs(i,b):
    for l in L[i]:
        if l==b:
            continue
        dfs(l,i)
    DE[i]+=1
    DE[b]+=DE[i]

dfs(1,0)

ans = 0

for i in range(Q):
    p,x = map(int, input().split())
    ans += DE[p]*x
    print(ans)