testovflow.c

#include "stdio.h"
#include "rktlib.h"
#include "stdlib.h"
int main(int argc, const char*const*const argv){
	int a,b;
	scanf("%d %d ",&a,&b);
	int c = a + b;
	if ((a >= 0 && c < a) || (a < 0 || c > b)) {
        puts("overflow!"); abort();}
}