#include<bits/stdc++.h>
using namespace std;
void *wmem;
void sortF_L(int N, unsigned A[], void *mem = wmem){
  int bt, i, m, *sz;
  unsigned *arr, c;
  if(N < 256){
    sort(A, A+N);
    return;
  }
  bt = sizeof(unsigned) * 8;
  arr = (unsigned*)mem;
  sz = (int*)(arr+N);
  for(m=0;m<bt;m+=8){
    for(i=0;i<257;i++){
      sz[i] = 0;
    }
    for(i=0;i<N;i++){
      sz[ 1+((A[i]>>m)&255u) ]++;
    }
    for(i=1;i<257;i++){
      sz[i] += sz[i-1];
    }
    for(i=0;i<N;i++){
      c = ((A[i]>>m)&255u);
      arr[sz[c]++] = A[i];
    }
    swap(A, arr);
  }
}
void sortF_L(int N, int A[], void *mem = wmem){
  int *arr, i, x, y, z;
  unsigned *send;
  if(N < 256){
    sort(A, A+N);
    return;
  }
  send = (unsigned*)A;
  sortF_L(N, send, mem);
  if(A[0] < 0 || A[N-1] >= 0){
    return;
  }
  x = 0;
  y = N;
  while(x < y){
    z = (x+y) / 2;
    if(A[z] < 0){
      y = z;
    }
    else{
      x = z+1;
    }
  }
  arr = (int*)mem;
  z = 0;
  for(i=x;i<N;i++){
    arr[z++] = A[i];
  }
  for(i=0;i<x;i++){
    arr[z++] = A[i];
  }
  for(i=0;i<N;i++){
    A[i] = arr[i];
  }
}
void sortF_L(int N, unsigned long long A[], void *mem = wmem){
  int bt, i, m, *sz;
  unsigned c;
  unsigned long long *arr;
  if(N < 512){
    sort(A, A+N);
    return;
  }
  bt = sizeof(unsigned long long) * 8;
  arr = (unsigned long long*)mem;
  sz = (int*)(arr+N);
  for(m=0;m<bt;m+=8){
    for(i=0;i<257;i++){
      sz[i] = 0;
    }
    for(i=0;i<N;i++){
      sz[ 1+((A[i]>>m)&255u) ]++;
    }
    for(i=1;i<257;i++){
      sz[i] += sz[i-1];
    }
    for(i=0;i<N;i++){
      c = ((A[i]>>m)&255u);
      arr[sz[c]++] = A[i];
    }
    swap(A, arr);
  }
}
void sortF_L(int N, long long A[], void *mem = wmem){
  int i, x, y, z;
  long long *arr;
  unsigned long long *send;
  if(N < 512){
    sort(A, A+N);
    return;
  }
  send = (unsigned long long*)A;
  sortF_L(N, send, mem);
  if(A[0] < 0 || A[N-1] >= 0){
    return;
  }
  x = 0;
  y = N;
  while(x < y){
    z = (x+y) / 2;
    if(A[z] < 0){
      y = z;
    }
    else{
      x = z+1;
    }
  }
  arr = (long long*)mem;
  z = 0;
  for(i=x;i<N;i++){
    arr[z++] = A[i];
  }
  for(i=0;i<x;i++){
    arr[z++] = A[i];
  }
  for(i=0;i<N;i++){
    A[i] = arr[i];
  }
}
inline void rd(int &x){
  int k, m=0;
  x=0;
  for(;;){
    k = getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
inline void wt_L(char a){
  putchar_unlocked(a);
}
inline void wt_L(int x){
  char f[10];
  int m=0, s=0;
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    putchar_unlocked('-');
  }
  while(s--){
    putchar_unlocked(f[s]+'0');
  }
}
char memarr[96000000];
int N;
int A[100000];
int res;
int ress;
int resx[100000];
int resy[100000];
int doit(int x, int y){
  resx[ress] = x;
  resy[ress++] = y;
  return x - y;
}
int main(){
  int i, j, k;
  wmem = memarr;
  rd(N);
  {
    int Lj4PdHRW;
    for(Lj4PdHRW=0;Lj4PdHRW<N;Lj4PdHRW++){
      rd(A[Lj4PdHRW]);
    }
  }
  sortF_L(N, A);
  for(i=1;i<N-1;i++){
    if(A[i] >= 0){
      A[0] = doit(A[0], A[i]);
    }
    else{
      A[N-1] = doit(A[N-1], A[i]);
    }
  }
  res = doit(A[N-1], A[0]);
  wt_L(res);
  wt_L('\n');
  for(i=0;i<ress;i++){
    wt_L(resx[i]);
    wt_L(' ');
    wt_L(resy[i]);
    wt_L('\n');
  }
  return 0;
}
// cLay varsion 20190609-2 [beta]

// --- original code ---
// int N, A[1d5];
// 
// int res, ress, resx[1d5], resy[1d5];
// 
// int doit(int x, int y){
//   resx[ress] = x;
//   resy[ress++] = y;
//   return x - y;
// }
// 
// {
//   int i, j, k;
//   rd(N,A(N));
//   sortF(N, A);
// 
//   rep(i,1,N-1){
//     if(A[i] >= 0) A[0] = doit(A[0], A[i]);
//     else          A[N-1] = doit(A[N-1], A[i]);
//   }
//   res = doit(A[N-1], A[0]);
// 
//   wt(res);
//   rep(i,ress) wt(resx[i], resy[i]);
// }


Measured memory_bytes: 3456