.M{
position:relative;
left:10px;
top:12.5px;
width:80px;
height:125px;
border-width:0 15px0 15px;
border-color:#000000;
border-style:solid}

.M::before{
position:absolute;
background-color:#000000;
content:'';
left:14px;
top:0;
width:12px;
height:110px;
-webkit-transform:skew(20deg,0);
-moz-transform:skew(20deg,0);
-ms-transform:skew(20deg,0);
-o-transform:skew(20deg,0);
transform:skew(20deg,0)}

.M::after{
transform:skew(-20deg,0);
position:absolute;
background-color:#000000;
content:'';
right:14px;
top:0;
width:12px;
height:110px}