/*2.718282Press any key to continue*/123456789101112131415161718192021#include <stdio.h> unsigned Fact(unsigned n) { unsigned i,fact = 1; for(i = 1; i <= n; ++i) fact *= i; return fact;} double Exp(int n) { double e = 1.0; int i; for(i = 1;i <= n;i++) e += 1.0/Fact(i); return e;} int main() { printf("%lf\n",Exp(20)); return 0;}