#include<stdio.h>

int main() { int a,b,c=0; scanf("%d %d",&a,&b); inti=1,j=0,k=1,x=1; while(i>0){ if(i<=1){ j=i; }else{ j=k+x; k=x; x=j; } if(j>=a&&j<=b){ c++; }else if(j>b){ break; } i++; } printf("%d",c);

return 0;

}