 Complete the following phrase:  As the defending champion of the FIFA U-20 World Cup does not gain automatic entry into the next biennial event, a curse purportedly affects the defending champions, preventing them from qualifying. This began in 1983, when West Germany, who won the championship in 1981, failed to qualify two years later. This also occurred in 1989 as defending champions Yugoslavia failed to qualify, 2001 with defending champions Spain, 