#include<stdio.h>
#include<stdlib.h>
int main()
{
int n = 0;
int ret = 0;
scanf("%d",&n);
ret = fib(n);
printf("%d\n", ret);
system("pause");
return 0;
}
tdio.h>
#include<stdlib.h>
int fib(int n)
{
int a = 1;
int b = 1;
int c = 1;
while (n > 2)
{
c = a + b;
a = b;
b = c;
n--;
}
return c;
}
int main()
{
int ret = 0;
int n = 0;
scanf("%d", &n);
ret = fib(n);
printf("%d", ret);
system("pause");
}