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.
    const first = maxTransform( A );
    const second = maxTransform( first );
    return second.reduce( ( a, e ) => a + e );
}

function maxTransform(A) {
    let B = [];
    const lengthOfA = A.length;
    for ( let k = 0; k<lengthOfA; k++ ) {
        for ( let i = 0; i<(lengthOfA - k); i++ ) {
            let j = i + k;
            let max = 0;
            for ( let m=i; m<=j; m++ ) {
                max = Math.max( max, A[ m ] );
            }
            B.push( max );
        }
    }
    return B;
}

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

}