// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');

function solution(N) {
  var max = 0,
      count = false,
      zeros = 0;

  while (N >= 1) {
    if (N % 2 === 0) {
      if (count) zeros += 1;
    }
    else {
      if (zeros > max) {
        max = zeros;
      }
      zeros = 0;
      count = true;
    }
    N = parseInt(N / 2);
  }

  return max;
}

// test result
var results = {
    total: 0,
    bad: 0
};

// function to test function
function test(functionToTest, args, expected) {
    results.total++;
    var result = functionToTest.apply(this, args);
    if (result !== expected) {
        results.bad++;
        console.log("Expected " + expected + ", but was " + result);
    }
}

// show results function
function showTestResults() {
    console.log("Of %d tests, %d failed, %d passed.", results.total, results.bad, (results.total - results.bad));
}

// test start
test(solution, [9], 2);
test(solution, [529], 4);
test(solution, [20], 1);
test(solution, [15], 0);
test(solution, [1041], 5);
test(solution, [0], 0);
test(solution, [1], 0);
test(solution, [66561], 9);
test(solution, [74901729], 4);
test(solution, [100000], 4);
test(solution, [51712], 2);

// show results
//showTestResults();