> round(runif(5)*10000000000)

[1] 4699722505 7338278117 9178197007 4576440312 8776889138

> a = numeric(length=100)

> for(i in 1:100){a[i] <- length(unique(round(runif(5000000)*10000000000)))}

> a

  [1] 4997123 4997071 4997014 4997117 4997097 4996992 4997121 4997105 4997135

 [10] 4997039 4997046 4997127 4997131 4997063 4997137 4997095 4997140 4997080

 [19] 4997092 4997073 4997104 4997162 4997153 4997115 4997060 4997094 4997086

 [28] 4997120 4997166 4997067 4997010 4997086 4997130 4997170 4997079 4997184

 [37] 4997056 4997081 4997156 4997110 4997174 4997036 4997154 4997107 4997029

 [46] 4997076 4997054 4997082 4997181 4997096 4997080 4997128 4997081 4997092

 [55] 4997137 4997082 4997121 4997194 4997056 4997101 4997058 4997144 4997025

 [64] 4997108 4997043 4997085 4997010 4997181 4997121 4997173 4997105 4997112

 [73] 4997073 4997107 4997059 4997133 4997042 4997139 4997057 4997003 4997031

 [82] 4997099 4997110 4997014 4997043 4997063 4997022 4997135 4997068 4997031

 [91] 4997030 4997172 4997018 4997033 4997114 4997007 4997042 4997034 4997161

[100] 4997066

> hist(a)