#include <stdio.h>
 
void souda(int a){
	static int c;
	c++;
}
int prime(int n){
	int i;
	int sosuu=1;
	for(i=2;i<n;i++){
		if(n%i==0){
			sosuu=0;
			break;
		}
	}
		return sosuu;
	}
 
 
 
int main(void){
	int i,a;
	for(i=2;i<20;i++){
	a=prime(i);
	if(a==1){
		souda(i);
	}
	}
	return 0;
}
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