# include <stdio.h>
int main(void){
    int x;
    scanf("%d",&x);
    int b;
    long int n;
    b=100;
    for(n=1;n<1000000000000;n++){
        b=b*1.01;
        
         if(b>=x){
            printf("%ld ",n);
            return 0;
        }
    }
    
}
    
