text: #include<stdio.h>
  #include<stdlib.h>
  #define CLS 2
  #define STU 3
  #define SUB 2
  #include<string.h>
  int main(){
  	int ary[CLS][STU][SUB]={1,2,3,4,5,6,7,8,9,10,11,12};
  	int i,j,k;
  	for(i=0;i<CLS;i++){
  		printf("class %d\n",i+1);
  		for(j=0;j<STU;j++){
  			printf(" stu %d:\n",j+1);
  			for(k=0;k<SUB;k++){
  				printf("  sub %d: ",k+1);
  				printf("%d\n",ary[i][j][k]);
  			}
  		}
  	}
  	return 0;
  }
  