Артем Кисленко

package main

import (
	"encoding/json"
	"fmt"
	"log"
)

type Attachment struct {
	Type string `json:"type"`
}

type CountOnly struct {
	Count int `json:"count"`
}

type vkResponseWallItem struct {
	Id          int          `json:"id"`
	FromId      int          `json:"from_id"`
	OwnerId     int          `json:"owner_id"`
	Date        int          `json:"date"`
	MarkedAsAds int          `json:"marked_as_ads"`
	PostType    string       `json:"post_type"`
	Text        string       `json:"text"`
	Attachment  Attachment   `json:"attachment"`
	Attachments []Attachment `json:"attachments"`
	Comments    CountOnly    `json:"comments"`
	Likes       CountOnly    `json:"likes"`
	Reposts     CountOnly    `json:"reposts"`
}

type Response struct {
	Response []json.RawMessage `json:"response"`
}

func main() {
	data := []byte(`{"response":[370,{"id":616,"from_id":-101299645,"to_id":-101299645,"date":1497367444,"marked_as_ads":0,"post_type":"post","text":"прайс актуален НО <br>АКЦИЯ \"знакомство с мастером\" - первое посещение любой дизайн бесплатно!! Спешите записаться, это будет не всегда))","can_delete":1,"can_pin":1,"is_pinned":1,"attachment":{"type":"photo","photo":{"pid":456239098,"aid":-7,"owner_id":-101299645,"user_id":100,"src":"https://pp.userapi.com/c637228/v637228340/56c6f/m_XTc7E9STE.jpg","src_big":"https://pp.userapi.com/c637228/v637228340/56c70/Jv0k8qYu1BU.jpg","src_small":"https://pp.userapi.com/c637228/v637228340/56c6e/ht4z4oVe-Jo.jpg","src_xbig":"https://pp.userapi.com/c637228/v637228340/56c71/0zpqUJ9BOBY.jpg","src_xxbig":"https://pp.userapi.com/c637228/v637228340/56c72/FQa5iNg2NnU.jpg","width":763,"height":1080,"text":"","created":1497367446,"post_id":616,"access_key":"9a6b6d3977113f56d0"}},"attachments":[{"type":"photo","photo":{"pid":456239098,"aid":-7,"owner_id":-101299645,"user_id":100,"src":"https://pp.userapi.com/c637228/v637228340/56c6f/m_XTc7E9STE.jpg","src_big":"https://pp.userapi.com/c637228/v637228340/56c70/Jv0k8qYu1BU.jpg","src_small":"https://pp.userapi.com/c637228/v637228340/56c6e/ht4z4oVe-Jo.jpg","src_xbig":"https://pp.userapi.com/c637228/v637228340/56c71/0zpqUJ9BOBY.jpg","src_xxbig":"https://pp.userapi.com/c637228/v637228340/56c72/FQa5iNg2NnU.jpg","width":763,"height":1080,"text":"","created":1497367446,"post_id":616,"access_key":"9a6b6d3977113f56d0"}}],"comments":{"count":0},"likes":{"count":1},"reposts":{"count":1}}]}`)

	var response Response
	err := json.Unmarshal(data, &response)
	if err != nil {
		log.Fatal(err)
	}

	var number int
	err = json.Unmarshal(response.Response[0], &number)
	if err != nil {
		log.Fatal(err)
	}

	var wallItem vkResponseWallItem
	err = json.Unmarshal(response.Response[1], &wallItem)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println("num:", number)
	fmt.Println("wall item:", wallItem)
}