2012素数判定

#include <stdio.h>#include <stdlib.h>#include <math.h>int is_prime(int n){    int i,sign=1;    for(i=2;i*i<=n;i++){        if(n%i==0)        sign=0;    }    if(sign==0) return 0;    else return 1;}int main(){    int x,y;    while(scanf("%d%d",&x,&y)!=EOF){        int n,m;        if(x==0&&y==0) break;        int count=0;        for(n=x;n<=y;n++){            m=pow(n,2)+n+41;            if(is_prime(m)){                count++;            }        }        if(count==y-x+1) printf("OK\n");        else printf("Sorry\n");    }    return 0;}