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Longest open run

A venue log uses O for an open hour and X for a closed hour. Read the log and print the longest consecutive run of O characters. If no hour was open, print zero.

Input

One line of 1 to 200 characters, each O or X.

Output

One integer: the longest consecutive open run.

Example 1

Input

OOXOOOXXO

Output

3

The middle three open hours form the longest run.

Constraints

  • 1 <= log length <= 200
  • The log contains only O and X

Hints

Hint 1 of 3

Track the current run separately from the best run.

Hint 2 of 3

Reset current when the status is X.

Hint 3 of 3

Update best after incrementing current.

Solution

Show a reference solution and explanation
 JavaScript · reference solution
const log = readline();
let best = 0;
let current = 0;
for (const status of log) {
  if (status === 'O') {
    current++;
    best = Math.max(best, current);
  } else {
    current = 0;
  }
}
console.log(best);

Why it works

The current counter describes the run ending at the present character. A closed hour breaks it, while the best counter keeps the largest run seen before that reset.

Lesson for this exercise: Loops in JavaScript: for, while, for...of and for...in

Your program
const log = readline();
let best = 0;
let current = 0;
// scan every status character
console.log(best);

Tests: 4 cases including the examples. Passing every test marks the exercise solved in this browser.

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