function tradeComm(input) {

    let city = input[0];
    let sales = Number(input[1]);
    if (0 <= sales && sales <= 500) {
        switch (city) {
            case 'Sofia': console.log((sales * 0.05).toFixed(2)); break;
            case 'Varna': console.log((sales * 0.045).toFixed(2)); break;
            case 'Plovdiv': console.log((sales * 0.055).toFixed(2)); break;
            default: console.log('error'); break;
        }
    } else if (500 < sales && sales <= 1000) {
        switch (city) {
            case 'Sofia': console.log((sales * 0.07).toFixed(2)); break;
            case 'Varna': console.log((sales * 0.075).toFixed(2)); break;
            case 'Plovdiv': console.log((sales * 0.08).toFixed(2)); break;
            default: console.log('error'); break;
        }
    } else if (1000 < sales && sales <= 10000) {
            switch (city) {
            case 'Sofia': console.log((sales * 0.08).toFixed(2)); break;
            case 'Varna': console.log((sales * 0.10).toFixed(2)); break;
            case 'Plovdiv': console.log((sales * 0.12).toFixed(2)); break;
            default: console.log('error'); break;
        }
    } else if (sales > 10000) {
        switch(city) {
            case 'Sofia': console.log((sales * 0.12).toFixed(2)); break;
            case 'Varna': console.log((sales * 0.13).toFixed(2)); break;
            case 'Plovdiv': console.log((sales * 0.145).toFixed(2)); break;
            default: console.log('error'); break;
        }
    }
      else{
      console.log('error');
      }
}