/*
TASK:minitime
LANG:C++
*/
#include <stdio.h>

int main(){
    int N,min=1000,i;
    int vreme[107];
        
    scanf("%d\n",&N);
    vreme[0]=N;
    min=vreme[0];
    for (i=1;i<N;i++) {
        vreme[i]=N/i+i+1;
        if (vreme[i]<min) {min=vreme[i];}
        }
   printf("%d",min);
   scanf("%d",min);
}
