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function processData(input) {
    

    let string = input.split('\n');
    let n = string[0];
    let arr = string[1].split(' ').map(Number);
    let new_arr = new Set()
    let pres ,pass = 0
    
    for(let i=0;i<n;i++){
       for(let j = 0;j<n;j++){
           
           if (Math.abs(arr[i] - arr[j]) == 1){
            // if (Math.abs(arr[i] - pres) == 1 && Math.abs(arr[i] - pass) == 1 || i==0){
                   new_arr.add(arr[i])
                   console.log(arr[i],arr[j])
                
     
           }
         
       if(true){
           new_arr.forEach((a,b)  =>{
              if(Math.abs(a - new_arr[b]) == 1){
                  console.log(a)
              }
           })
       }
       }
    }
    
}
            
process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
    processData(_input);
});