瓷砖

var line =readline().split('');

~function(){
    var obj ={};
    line.forEach(function(item){
        obj[item]=null;
    });
    var len =Object.keys(obj).length;
    if(len<=2){
        print(len);
    }else{
        print(0);
    };
}();

最长子串

var line =readline();

~function(){
    var len =0;
    var lenSet =[];
    if(line.length<=1){
        print(line.length);
        return;
    };
    for(var i=1 ;i<line.length ;i++){
        if(line[i-1]!==line[i]){
            len++;
        }else{
            lenSet.push(len+1);
            len=0;
        };
    };
    lenSet.push(len+1);
    len =Math.max.apply(Math,lenSet);

    print(len);
}();

生存天数

var arr =readline().split(' ').map(function(item){
    return +item;
});

var x =arr[0];//每天的租金
var f =arr[1];//已有水果
var d =arr[2];//手里的钱
var p =arr[3];//水果售价

~function(){
    var days =0;
    if(f>0){
        days =Math.min(
            f,
            Math.floor(d/x)
        );
        d -=days*x;
    };
    days +=Math.floor(d/(x+p));
    print(days)
}();