function Main(input) {
    var line = input.split(' ').map(Number);
    var A = line[0];
    var B = line[1];
    var C = line[2];
    var val = 0;

    if ((A - 1 + B) < C) {
       val = Math.ceil(C / ((A - 1) + B)) * A;    
    }
    console.log(val);
}

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