// 기본 입출력 셋팅
var fs = require('fs');
var stdin = fs.readFileSync('/dev/stdin', 'utf8');
var input = stdin.match(/[^\r\n]+/g)[0];
var stack = [];
var count = 0;

for(var i = 0; i< input.length; i++) {
    if (input[i] === "(") {
        stack.push(i);
    } else if (input[i] === ")") {
        var pos = stack.pop();
        if (pos + 1 === i) {
            count += stack.length;
        } else {
            count += 1;
        }
    }
}
console.log(count);