function main(input) {
	let val = 100;
	let a = 1;
	while (true) {
		val += Math.floor(val * 0.01)
		if (val >= input) {
			console.log(a);
			break;
		}
		a += 1;
	}
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));