Language: C

#include<stdio.h>
int main()
{
    int m,f,r;
    while(1)
    {
        scanf("%d %d %d",&m,&f,&r);
        if(m==-1 && f==-1 && r==-1)
        {
            break;
        }
        if(m==-1 || f==-1 || (m+f)<30)
        {
            printf("F\n");
        }
        else if((m+f)>=80)
        {
            printf("A\n");
        }
         else if((m+f)>=65 && (m+f)<80)
        {
            printf("B\n");
        }
         else if((m+f)>=50 && (m+f)<65 || r>=50)
        {
            printf("C\n");
        }
         else if((m+f)>=30 && (m+f)<50)
        {
            printf("D\n");
        }
 
    }
    return 0;
}


Compiler output:
main.c: In function 'main':
main.c:4:1: error: stray '\302' in program
    4 | <U+00A0><U+00A0><U+00A0><U+00A0>int m,f,r;
      | ^~~~~~~~
main.c:4:2: error: stray '\302' in program
    4 | <U+00A0><U+00A0><U+00A0><U+00A0>int m,f,r;
      |         ^~~~~~~~
main.c:4:3: error: stray '\302' in program
    4 | <U+00A0><U+00A0><U+00A0><U+00A0>int m,f,r;
      |                 ^~~~~~~~
main.c:4:4: error: stray '\302' in program
    4 | <U+00A0><U+00A0><U+00A0><U+00A0>int m,f,r;
      |                         ^~~~~~~~
main.c:5:1: error: stray '\302' in program
    5 | <U+00A0><U+00A0><U+00A0><U+00A0>while(1)
      | ^~~~~~~~
main.c:5:2: error: stray '\302' in program
    5 | <U+00A0><U+00A0><U+00A0><U+00A0>while(1)
      |         ^~~~~~~~
main.c:5:3: error: stray '\302' in program
    5 | <U+00A0><U+00A0><U+00A0><U+00A0>while(1)
      |                 ^~~~~~~~
main.c:5:4: error: stray '\302' in program
    5 | <U+00A0><U+00A0><U+00A0><U+00A0>while(1)
      |                         ^~~~~~~~
main.c:6:1: error: stray '\302' in program
    6 | <U+00A0><U+00A0><U+00A0><U+00A0>{
      | ^~~~~~~~
main.c:6:2: error: stray '\302' in program
    6 | <U+00A0><U+00A0><U+00A0><U+00A0>{
      |         ^~~~~~~~
main.c:6:3: error: stray '\302' in program
    6 | <U+00A0><U+00A0><U+00A0><U+00A0>{
      |                 ^~~~~~~~
main.c:6:4: error: stray '\302' in program
    6 | <U+00A0><U+00A0><U+00A0><U+00A0>{
      |                         ^~~~~~~~
main.c:7:1: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      | ^~~~~~~~
main.c:7:2: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      |         ^~~~~~~~
main.c:7:3: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      |                 ^~~~~~~~
main.c:7:4: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      |                         ^~~~~~~~
main.c:7:5: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      |                                 ^~~~~~~~
main.c:7:6: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      |                                         ^~~~~~~~
main.c:7:7: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      |                                                 ^~~~~~~~
main.c:7:8: error: stray '\302' in program
    7 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>scanf("%d %d %d",&m,&f,&r);
      |                                                         ^~~~~~~~
main.c:8:1: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      | ^~~~~~~~
main.c:8:2: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      |         ^~~~~~~~
main.c:8:3: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      |                 ^~~~~~~~
main.c:8:4: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      |                         ^~~~~~~~
main.c:8:5: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      |                                 ^~~~~~~~
main.c:8:6: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      |                                         ^~~~~~~~
main.c:8:7: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      |                                                 ^~~~~~~~
main.c:8:8: error: stray '\302' in program
    8 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 && f==-1 && r==-1)
      |                                                         ^~~~~~~~
main.c:9:1: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      | ^~~~~~~~
main.c:9:2: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      |         ^~~~~~~~
main.c:9:3: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      |                 ^~~~~~~~
main.c:9:4: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      |                         ^~~~~~~~
main.c:9:5: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      |                                 ^~~~~~~~
main.c:9:6: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      |                                         ^~~~~~~~
main.c:9:7: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      |                                                 ^~~~~~~~
main.c:9:8: error: stray '\302' in program
    9 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>{
      |                                                         ^~~~~~~~
main.c:10:1: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      | ^~~~~~~~
main.c:10:2: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |         ^~~~~~~~
main.c:10:3: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                 ^~~~~~~~
main.c:10:4: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                         ^~~~~~~~
main.c:10:5: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                 ^~~~~~~~
main.c:10:6: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                         ^~~~~~~~
main.c:10:7: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                                 ^~~~~~~~
main.c:10:8: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                                         ^~~~~~~~
main.c:10:9: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                                                 ^~~~~~~~
main.c:10:10: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                                                         ^~~~~~~~
main.c:10:11: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                                                                 ^~~~~~~~
main.c:10:12: error: stray '\302' in program
   10 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>break;
      |                                                                                         ^~~~~~~~
main.c:11:1: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      | ^~~~~~~~
main.c:11:2: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      |         ^~~~~~~~
main.c:11:3: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      |                 ^~~~~~~~
main.c:11:4: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      |                         ^~~~~~~~
main.c:11:5: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      |                                 ^~~~~~~~
main.c:11:6: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      |                                         ^~~~~~~~
main.c:11:7: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      |                                                 ^~~~~~~~
main.c:11:8: error: stray '\302' in program
   11 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>}
      |                                                         ^~~~~~~~
main.c:12:1: error: stray '\302' in program
   12 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 || f==-1 || (m+f)<30)
      | ^~~~~~~~
main.c:12:2: error: stray '\302' in program
   12 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 || f==-1 || (m+f)<30)
      |         ^~~~~~~~
main.c:12:3: error: stray '\302' in program
   12 | <U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0><U+00A0>if(m==-1 || f==-1 || (m+f)<30)
      |                 ^~~~~~~~
main.c:12:4: error: stray '\302' in program
   12 | <U+00A0><U