Language: C

#include <stdio.h>
int main(void)
{
	int M,h[101]m[101],N,k[101],g[101],L,i,j,a=0,b=0,c=0,zi[202]={0},pun[202]={0};
	for(i=0;i<100;i++){
		h[i]=999;
		m[i]=999;
		k[i]=999;
		g[i]=999;
	}
	scanf("%d",&M);
	for(i=0;i<M;i++){
		scanf("%d %d",&h[i],&m[i]);
	}
	scanf("%d",&N);
	for(j=0;j<N;j++){
		scanf("%d %d",&k[j],&g[j]);
	}
	L=M+N;
	for(i=0;i<L;i++){
		if(h[a]>k[b]||m[a]>g[b]){
			zi[c]=k[b];
			pun[c]=g[b];
			b++;
			c++;
		}
		else if(k[b]>h[a]||g[b]>m[a]){
			zi[c]=h[a];
			pun[c]=m[a];
			a++;
			c++;
		}
		else{
			zi[c]=h[a];
			pun[c]=m[a];
			a++;
			zi[c]=k[b];
			pun[c]=g[b];
			b++;
			c++;
		}
		if(a==M&&b==N){
			break;
		}
	}
	for(j=0;j<c;j++){
		if(pun[j]<=9){
			printf("%d:0%d",zi[j],pun[j]);
		}
		else{
			printf("%d:%d",zi[j],pun[j]);
		}
		if(j<c-1){
			printf(" ");
		}
		else{
			printf("\n");
		}
	}
	return 0;
}

Compiler output:
main.c: In function 'main':
main.c:4:21: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'm'
    4 |         int M,h[101]m[101],N,k[101],g[101],L,i,j,a=0,b=0,c=0,zi[202]={0},pun[202]={0};
      |                     ^
main.c:4:73: error: expected expression before ',' token
    4 |         int M,h[101]m[101],N,k[101],g[101],L,i,j,a=0,b=0,c=0,zi[202]={0},pun[202]={0};
      |                                                                         ^
main.c:4:74: error: 'pun' undeclared (first use in this function)
    4 |         int M,h[101]m[101],N,k[101],g[101],L,i,j,a=0,b=0,c=0,zi[202]={0},pun[202]={0};
      |                                                                          ^~~
main.c:4:74: note: each undeclared identifier is reported only once for each function it appears in
main.c:5:13: error: 'i' undeclared (first use in this function)
    5 |         for(i=0;i<100;i++){
      |             ^
main.c:6:17: error: 'h' undeclared (first use in this function)
    6 |                 h[i]=999;
      |                 ^
main.c:7:17: error: 'm' undeclared (first use in this function)
    7 |                 m[i]=999;
      |                 ^
main.c:8:17: error: 'k' undeclared (first use in this function)
    8 |                 k[i]=999;
      |                 ^
main.c:9:17: error: 'g' undeclared (first use in this function)
    9 |                 g[i]=999;
      |                 ^
main.c:15:21: error: 'N' undeclared (first use in this function)
   15 |         scanf("%d",&N);
      |                     ^
main.c:16:13: error: 'j' undeclared (first use in this function)
   16 |         for(j=0;j<N;j++){
      |             ^
main.c:19:9: error: 'L' undeclared (first use in this function)
   19 |         L=M+N;
      |         ^
main.c:21:22: error: 'a' undeclared (first use in this function)
   21 |                 if(h[a]>k[b]||m[a]>g[b]){
      |                      ^
main.c:21:27: error: 'b' undeclared (first use in this function)
   21 |                 if(h[a]>k[b]||m[a]>g[b]){
      |                           ^
main.c:22:25: error: 'zi' undeclared (first use in this function)
   22 |                         zi[c]=k[b];
      |                         ^~
main.c:22:28: error: 'c' undeclared (first use in this function)
   22 |                         zi[c]=k[b];
      |                            ^