////////////////////// 111111

 let a = 1;
 let k = 1
for (let k = 1; k <= 100; k++){
    a += k
}
console.log( a )
////////////////22222222222222
let x = 1467
let y;
let count = 0
for ( x ; x > 0; ){
    y = x % 10;
    x = parseInt( x / 10);
    count += y
}
console.log( count )
///////////////////3333333333333


x  = 10
y = 50
count = 10
for ( ; x <= y ; ){
    x += 2
    count += x
}
console.log( count )
/////////////444444444444444444


x = 10
for (y = 1 ; y <= x ; y ++){
    for (k = y - 1 ; k >= 0 ; k--){
        console.log ( y )
    }
}
/////////////////////5
let fib1 = 1
let fib2 = 1
let fib3
count = 1
for (k = 6 ; k > 0 ; k --){
    fib3 = fib1 + fib2
    fib1 = fib2
    fib2 = fib3
}
console.log( fib3 )
//////////////////6666666666

let x = 5
for (let k = 1 ; k < x ; k++){
    x *= k
}
console.log( x )
/////////////77777777777
 x = 4
let y = 2
let a = y, b = x
for (k = y-1 ; k > 1 ; k--){

    a *= k
}
console.log(a)
for (k = x-1 ;k > 1; k--){

    b *= k
}
console.log(b)
let some = k
for (k = x - y - 1; k> 1; k--){
    some *= k
}
console.log(some)
let comb = parseInt (b / ( some * a))
console.log (comb)
//////////////////////8888888888888
a = 13
k = 0
for (let del = 2 ; del < a ; del ++){
    if ( a % del == 0){
        k++
    }
}
if ( k >= 0 ){
    console.log(a + " Число простое")
}
else {
    console.log(a + " Не простое число")
}