f I write a loop that loops 20 times, and inside the loop adds 1 to a variable, then enclose all that in a loop that loops 20 times, what am I adding to the variable in total, after all the loops.

int number = 0;

for(int i = 0; i < 20; i++) {

for(int j = 0; j < 20; j++) {

number = number + 1;

}