function experienceGaining(input) {

    let neededExperience = input.shift();
    let countOfBattles = input.shift();


    let collectedExperience = 0;
    let battleCount = 0

    for (let i = 0; i < input.length; i++) {
        battleCount++
        let currExp = input[i];


        if (battleCount % 3 !== 0 && battleCount % 5 !== 0 && battleCount % 15 !== 0) {
            collectedExperience += currExp
        }

        if (battleCount % 3 === 0) {

            collectedExperience += currExp + (currExp * 0.15);
        }

        if (battleCount % 5 === 0) {

            collectedExperience += currExp - (currExp * 0.1);
        }

        if (battleCount % 15 === 0) {

            collectedExperience += currExp + (currExp * 0.5);
        }
        if (collectedExperience >= neededExperience) {
            break;
        }

    }
    if (collectedExperience >= neededExperience) {
        console.log(`Player successfully collected his needed experience for ${battleCount} battles.`);
    } else {
        console.log(`Player was not able to collect the needed experience, ${(neededExperience - collectedExperience).toFixed(2)} more needed.`);

    }
}