"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const N = parseInt(arg[0]);
    const S = (arg[1].split(" ")[0]);
    const T = (arg[1].split(" ")[1]);
    
    let answer = [];
    
    for(let i=0; i<N; i++) {
        answer.push(S[i]);
        answer.push(T[i]);
    }
    
    console.log(answer.join(""));
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));