process.stdin.resume();
process.stdin.setEncoding('utf8');
process.stdin.on('data', function(chunk) {
    main(chunk.trim());
});

function main(chunk){
    // your code goes here
    var lines = chunk.split("\n");
    var n = Number(lines[0]);
    var blocks = lines[1].split(" ");
    var object = {};
    for(var i in blocks){
        object[Number(blocks[i])] = Number(i);
    }
    var tmp = n;
    var ans;
    for(ans = n;ans>0;ans--){
        if(object[ans] > tmp){
            break;
        }
        tmp = object[ans];
    }
    console.log(ans);
}