#include<iostream>
#include<stdio.h>

struct Base {         
    int v1;
//    private:   //error!
        int v3;
    public:     //显示声明public
        int v2;
    void print(){       
        printf("%s\n","hello world");
    };    
};

int main() {
    struct Base base1;  //ok
    Base base2; //ok
    Base base;
    base.v1=1;
    base.v3=2;
    base.print();
    printf("%d\n",base.v1);
    printf("%d\n",base.v3);
    return 0;
}