def main():
    N,Q = map(int,input().split())
    G = [[] for _ in range(N)]
    for i in range(N-1):
        a,b = map(int,input().split())
        a -= 1; b -= 1
        G[a].append(b)
        G[b].append(a)
    chi = [0]*N
    par = [0]*N
    par[0] = -1
    stack = []
    stack.append(~0)
    stack.append(0)
    while stack:
        v = stack.pop()
        if v >= 0:
            for u in G[v]:
                if u == par[v]: continue
                par[u] = v
                stack.append(~u)
                stack.append(u)
        else:
            v = ~v
            ret = 1
            for u in G[v]:
                ret += chi[u]
            chi[v] = ret
    #print(chi)
    ans = 0
    for i in range(Q):
        p,x = map(int,input().split())
        p -= 1
        ans += chi[p]*x
        print(ans)


if __name__ == '__main__':
    main()