*{
    padding: 0;
    margin: 0;
}

.box{
    width: 600px;
    height: 800px;
    margin:50px auto;
    position: relative;
}

.A{
    width: 150px;
    height: 250px;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 99;
    
}
.B{
    width: 150px;
    height: 250px;
    position: absolute;
    top: 0;
    right: 0;
    z-index: 99;
}
.C{
    width: 150px;
    height: 250px;
    position: absolute;
    bottom: 0;
    left: 0;
    z-index: 99;
}
.D{
    width: 150px;
    height: 250px;
    position: absolute;
    bottom: 0;
    right: 0;
    z-index: 99;

    
}

img{
    width: 100%;
    height: 100%;
}

.bigIMg{
    width: 250px;
    height: 400px;
  
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translateX(-50%) translateY(-50%);

}