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)) .
    var S = solve1(A)
    var SS = solve1(S);
    var sum = SS.reduce((total, num) => total+num)
    return sum
}

function solve1(A) {
    //  Return the sum of S(S(A)) .
    var B = [];
    for(var k=0; k<A.length; k++){
        for (var i=0; i<A.length-k; i++){
            var j = i+k;
            var newArr = A.slice(i, j+1);
            if (newArr.length === 1 ){
                B.push(newArr[0])
            }
            if (newArr.length > 1){  
                B.push(Math.max(...newArr))
            }
        }
    }
    return B
}

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

}