func_code_string: #include <bits/stdc++.h>   using namespace std;   int T, n, m, sa[40010], sb[40010], ls, du[201], ans;   bool g[201][201];   int getint() {     int w = 0;     bool q = 0;     char c = getchar();     while ((c >  9  || c <  0 ) && c !=  - ) c = getchar();     if (c ==  - ) c = getchar(), q = 1;     while (c >=  0  && c <=  9 ) w = w * 10 + c -  0 , c = getchar();     return q ? -w : w;   }   void dfs(int u) {     while (du[u]) {       for (int i = 1; i <= n; i++)         if (g[u][i]) {           ls++;           sa[ls] = u;           sb[ls] = i;           du[u]--, du[i]--;           g[u][i] = g[i][u] = 0;           u = i;           break;         }     }   }   int main() {     T = getint();     while (T--) {       ans = n = getint();       m = getint();       for (int i = 1, x, y; i <= m; i++) {         x = getint();         y = getint();         g[x][y] = g[y][x] = 1;         du[x]++;         du[y]++;       }       for (int i = 1; i <= n; i++) ans -= du[i] & 1;       printf( %d n , ans);       for (int i = 1; i <= n; i++)         if (du[i] & 1)           while (du[i]) dfs(i);       for (int i = 1; i <= n; i++)         while (du[i]) dfs(i);       for (int i = 1; i <= ls; i++) printf( %d %d n , sa[i], sb[i]);       ls = 0;     }   }   