#include <stdio.h>
    union Un
    {
        struct
        {
            unsigned char c : 1;
            unsigned int n : 2;
        }Stru;
        int ch;
    };
    int main()
    {
        union Un u;
        u.Stru.c = 1;
        printf("%d\n", u.Stru.c);
    }