#include<stdio.h>
int sqrt(int x)
{
    long long low=0,mid = 0;
    long long high = (long long)x;
    while(low<=high){
        mid = (low + high)/2;
        if(mid*mid == x) return mid;
        if(mid*mid < x && (mid+1)*(mid+1) > x)
        { 
           return mid ;
        }
        if(mid*mid > x && (mid-1)*(mid-1) < x)
        {
            return mid -1;
        }
        if(mid*mid > x){
            high = mid - 1;
        }else{
            low = mid + 1;
        }
    }
    return (int)mid;  
}

int main()
{
    long long a = 0;
    while(scanf("%lld",&a)!=EOF)
    {
        printf("%d\n",sqrt(a));
    }
    return 0;
}