#include<stdio.h>
//四个数比较大小(冒泡排序由小到大)
/*核心思想:变量寄存，两两比较*/

int main(int argc,char *argv[]){
    
    int a,b,c,d,num;
    scanf("%d%d%d%d",&a,&b,&c,&d);
    if(a>b){num=a;a=b;b=num;}
    if(a>c){num=a;a=c;c=num;}
    if(a>d){num=a;a=d;d=num;}
    
    if(b>c){num=b;b=c;c=num;}
    if(b>d){num=b;b=d;d=num;}
    
    if(c>d){num=c;c=d;d=num;}
    printf("比较大小:%d<%d<%d<%d\n",a,b,c,d);
    
}