class String {
	constructor(innerString, innerLength) {
		this.innerString = innerString;
		this.innerLength = innerLength
	}
	
	get innerLength() {
		return this._innerLength;
	}
	
	set innerLength(value) {
		if (value < 0) {
			this._innerLength = 0;
		} else {
			this._innerLength = value;
		}
	}
	
	increase(length) {
		this.innerLength += length;
	}
	
	decrease(length) {
		this.innerLength -= length;
	}
	
	toString() {
		if (this.innerString.length < this.innerLength) {
			return this.innerString;
		}
		
		return this.innerString.substring(0,this.innerLength) + '...';
	}
}