#include <limits.h>

int safeAdd(int i, int j, bool& flag) {
  flag = true; // make sure this always has some value

  if(i < 0) {
    if(INT_MIN - i < j) { // no underflow
      return i + j;
    }
  } else {
    if(INT_MAX - i > j) { // no overflow
      return i + j;
    }
  }
  flag = false;
  return i;
}
  
int safeMul(int i, int j, bool& flag) {
  flag = true; // make sure this always has some value

  // make j non-negative
  if(j < 0) {
    j = -j;
    i = -i;
  }

  if(j == 0) {
    return 0;
  } else if(j == 1) {
    return i;
  } else {
    int big = safeAdd(i, i, flag);
    if(!flag) {
      return i;
    }
    big = safeMul(big, j/2, flag);
    if(!flag) {
      return i;
    }
    if(j%2) { // j is odd
      big = safeAdd(big, i, flag);
      if(!flag) {
        return i;
      }
    }
    return big;
  }
}