process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////

function solve(A) {
    //  Return the sum of S(S(A)) modulo 10^9+7.
    var B =[];
    for(k=0; k<=A.length-1; k++){
        for(i=0; i<=((A.length)-(k+1)); i++){
            var j =i+k;
            var tem =[];
            for(a=i; a<=j; a++){ 
            tem.push(A[a]);     
            }
            B.push(Math.max.apply(Math,tem));
        }
    }
    var C =[];
      for(k=0; k<=B.length-1; k++){
        for(i=0; i<=B.length-k-1; i++){
            var j =i+k;
                        var tem =[];
             for(a=i; a<=j; a++){
                 tem.push(B[a]);
             }
            C.push(Math.max.apply(Math,tem));
            }           
        }
        var sum =0;
    for(i=0; i<C.length; i++){
      sum += C[i];  
    }
    return sum;
}

function main() {
    var n = parseInt(readLine());
    a = readLine().split(' ');
    A = a.map(Number);
    var result = solve(A);
    process.stdout.write("" + result + "\n");

}