var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

var lines = [];
reader.on('line',(line) => {
          lines.push(line);
});

reader.on('close', () => {
          var s = lines[0];
  var a = [s];
  for (var i = 0; i < 1000010; i++){
    if (a[i] % 2 == 0){
     a.push( a[i] / 2 );
    } else {
      a.push( a[i]*3+1 );
    }
    for (var j = 0; j < i;j++){
      if (a[i] == a[j]){
         console.log(i+1);
        return;
      }
    }
  }
});