X<-c("B","C","D","E","F","G","H","I","J","K","L","M","N")

X1<-sample(X,1000,replace=T)`
X2<-sample(X,1000,replace=T)
X3<-sample(X,1000,replace=T)
X4<-sample(X,1000,replace=T)
X5<-sample(X,1000,replace=T)
X6<-sample(X,1000,replace=T)
X7<-sample(X,1000,replace=T)
X8<-sample(X,1000,replace=T)
data<-data.frame(X1,X2,X3,X4,X5,X6,X7,X8)
summary(data)