console.log(abbrev_name("Robin Singh"));

function abbrev_name(str)
{
    var temp = str.split('');
    var ar = [];
    for(var i =0 ; i<temp.length ; i++)
    {
       // ar.push(temp[i]);
        if(temp[i] == ' ')
        {
            ar.push(temp[i])
            ar.push(temp[i+1]);
            break;
        }
         ar.push(temp[i]);
        
    }
    return ar.join('');
}