>>301
f <- function(N){
+ a=numeric()
+ a[1]=0
+ a[2]=0
+ # a[3]=(a[1]-1)%%100
+ # a[4]=(a[2]-1)%%100
+ for(n in 2:N){
+ a[n+1]=(a[n-1]-1)%%100
+ }
+ a[N]
+ }
> f(100)
[1] 51