class dictionary{
    constructor(m){
        this.S = new Array(m);
        this.m = m;
    }
    
    h1(key){
        return key % this.m;
    }
    h2(key){
        return 1 + key % (this.m-1);
    }
    h(key,i){
        return (this.h1(key)+i*this.h2(key)) % this.m;
    }
    insert(key){
        let i = 0;
        while(true){
            let j = this.h(key,i);
            if(typeof this.S[j]==="undefined"){
                this.S[j] = key;
                return j;
            }else{
                i++;
            }
        }
    }
    search(key){
        let i = 0;
        while(true){
            let j = this.h(key,i);
            if(this.S[j]===key){
                return j;
            }else if(i>=this.m || typeof this.S[j]==="undefined"){
                return false;
            }else{
                i++;
            }
        }
    }
}

function main(input){
    let lines = input.trim().split("\n");
    let length = parseInt(lines.shift());
    let dict = new dictionary(length);

    for(let i =0;i<length;i++){
        let args = lines[i].trim().split(" ");
        args[1] = args[1].replace(/A/g,"1");
        args[1] = args[1].replace(/C/g,"2");
        args[1] = args[1].replace(/G/g,"3");
        args[1] = args[1].replace(/T/g,"4");


        if(args[0]==="insert"){
            dict.insert(parseInt(args[1]));
        }else if(args[0]==="find"){
            let res = dict.search(parseInt(args[1]));
            if(typeof res==="number") console.log("yes");
            else console.log("no");
        }
        
    }
    
}

main(require("fs").readFileSync("/dev/stdin","utf-8"));
