var lines=[];
var reader = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
});
reader.on('line', function (line) {
  lines.push(line);
});
reader.on('close', function () {
  var target=lines[0]-0;
  var biscuitInPocket=1;
  var remainBiscuit=target-1;
  var tapped=0;
  while(remainBiscuit>0) {
     if (biscuitInPocket<=remainBiscuit    ) {
        tapPocket();
     } else {
        biscuitInPocket=remainBiscuit;
     }
  }
  console.log(tapped);
  function tapPocket() {
     remainBiscuit-=biscuitInPocket;
     biscuitInPocket*=2;
     tapped++;
  }
});