#include <stdio.h>
#define N 20
#include <string.h>
int main(void) {
    char str[N],substr[N];
    int i=0,start=6,len=8;
    printf("\n请输入身份证号：");
    fgets (str, sizeof(str), stdin);
    for(;i<len;i++)
       substr[i]=str[start+i];
    substr[len]='\0';
    printf("对应出生日期为%s\n",substr);
	// your code goes here
	return 0;
}